The Ministry of Magic (M.o.M.) is the United Kingdom government department responsible for all the witches and wizards in the country and for keeping their existence a secret from Muggles. This breaks down into a range of things, including keeping magical creatures hidden and creating and managing magical spaces where witches and wizards can enjoy their own facilities.
The Ministry of Magic Headquarters is located underground, in the heart of London. There are several ways to enter the Ministry, including Floo Powder and Apparition, or by using one of the entrances.
 Visitors' Entrance
The visitors' entrance can be accessed via an apparently out of order public telephone; visitors need only dial 62442 and declare their name and business, after which a badge bearing that information is issued from the returned coins cute. They would then be asked to attach the badge to the front of their robes as the telephone booth descends underground into the Atrium.
 Employees' Entrance During Voldemort's Reign
During the period in which Lord Voldemort had control of the Ministry between August 1997 and May 1998, Ministry employees were forced to use an entrance located in a public underground toilet. They would use a golden token to access a stall, stand in the toilet and flush themselves down, which would send them down a chute and out of one of the Atrium's many fireplaces.
 Levels and Departments
The Ministry Headquarters are made up of several levels, each of them home to a specific department, with the exception of the Atrium and the courtrooms.
 Level One, Minister of Magic and Support Staff
 The Minister for Magic
The Minister for Magic is the political leader of the magical world. The Minister occasionally reports to the Muggle Prime Minister, to inform the latter of important developments, including the appointment of new Ministers.
 Level Two, Department of Magical Law Enforcement
The Department of Magical Law Enforcement is responsible for upholding and maintaining wizarding law, which includes monitoring and preventing illegal activities and apprehending perpetrators. This department includes the Improper Use of Magic Office, the Auror Headquarters, and the Wizengamot Administration Services. It also includes the Misuse of Muggle Artefacts Office and, as of 1996, the Office for the Detection and Confiscation of Counterfeit Defensive Spells and Protective Objects.
 Level Three, Department of Magical Accidents and Catastrophies
The Department of Magical Accidents and Catastrophies is responsible for handling the aftermaths of all sorts of magic-related accidents. This department includes the Accidental Magical Reversal Squad, Obliviator Headquarters, and the Muggle-Worthy Excuse Committee.
The Department for the Regulation and Control of Magical Creatures is responsible for keeping track of magical creatures as well as classifying them and keeping them out of Muggle sight. This department incoporates Beast, Being and Spirit Divisions and has the Goblin Liason Office and Pest Advisory Bureau.
Known Heads of this department include Hermione Granger.
 Level Five, Department of International Magical Co-operation
The Department of International Magical Cooperation handles all international affairs and organizes international events such as the Quidditch World Cup and the Triwizard Tournament. This department includes the International Magical Trading Standards Body, the International Magical Office of Law and the International Confederation of Wizards, British Seats.
Known Heads of this department include Barty Crouch, Sr
 Level Six, Department of Magical Transportation
The Department of Magical Transport monitors and regulates all forms of magical transportation. This department includes the Floo Network Authority, Broom Regulatory Control, Portkey Office and Apparation Test Centre.
 Level Seven, Department of Magical Games and Sports
The Department of Games and Sports is responsible for organizing and monitoring wizarding games and sports, such as Quidditch. This department includes the British and Irish Quidditch League Headquarters, Official Gobstones Club and Ludicrous Patents Office.
Known Heads of this department include Ludovic Bagman.
 Level Eight, The Atrium
The Atrium is the entrance hall of the Ministry Headquarters. It is the level first encountered by anyone who arrives by using the visitor's entrance or Floo Powder, among other means. It is described as a long hall with a polished wooden floor and walls and a blue ceiling with ever-changing golden symbols. Along the walls are fireplaces used to travel to and from the Ministry through Floo Powder; one wall is used for arrivals, and the other for departures. The Security Desk, also located in the Atrium, is where visitors are inspected with a Secrecy Sensor and have their wands checked in. Located in a small hall the end of the Atrium are around twenty lifts behind golden grilles.
 The Fountain of Magical Brethren
The Fountain of Magical Brethren is located halfway down the Atrium. It is composed of a large circular pool with a group of large golden statues of a wizard with his wand in the air, a witch, a centaur, a goblin, and a house-elf standing in the center, supposedly representing unity between wizards and magical creatures of all kinds, with jets of water shooting out of the tips of the witch and wizard's wands, the centaur's arrow, the house-elf's ears, and the goblin's hat. All coins tossed into the fountain are donated to St. Mungo's Hospital for Magical Maladies and Injuries.
 During Voldemort's Reign
During the period in which Lord Voldemort had control of the Ministry between August 1997 and May 1998, the Atrium looked vastly different. It was much darker, and the Fountain of Magical Brethren was replaced with a large statue made of black stone, of a witch and a wizard seated on thrones made of naked Muglles, with the words "MAGIC IS MIGHT" engraved at the bottom.
 Level Nine, Department of Mysteries
The work in the Department of Mysteries is top secret. Employees who work there, known as Unspeakables, study a large number of mysterious things including time, death, prophecy, and the power of love..
 Level Ten, The Courtrooms
Level ten is the only level that cannot be reached by lifts, but by taking a flight of stairs just to the left of the door leading to the Department of Mysteries. The courtrooms are where criminals are tried, usually seated and chained, before the Wizengamot and a jury.