Ministry of Magic

Departments
Different departments comunicate through "Interdepartmental memos", pale-violet paper aeroplanes that fly on their own to destinations. They once used owls, but the mess was unbelievable.
 * Department of Magical Law Enforcement
 * Department of Magical Games and Sports
 * Department of Magical Accidents and Catastrophes
 * Department of Magical Transportation
 * Department for the Regulation and Control of Magical Creatures
 * Department of International Magical Cooperation
 * Department of Education
 * Department of Mysteries

Level 1- Minister for Magic and Support Staff and the Department of Education
This department has the offices of the highest ministry officials. It includes the following known offices: This department also holds the offices for the Department of Education.
 * Office of the Minister for Magic
 * Office of the Advisor to the Minister
 * Office of the Senior Undersecretary to the Minister for Magic
 * Office of the Junior Assistant to the Minister for Magic
 * Wizarding Examinations Authority

Level 3 - Department of Magical Accidents and Catastrophes
The Department of Magical Accidents and Catastrophes is responsible for reapiring accidental magical damage. It includes the following known departments:

A Study into Muggle Suspicion about Magic
A Study into Muggle Suspicion about Magic was a report produced by a committee of the Ministry of Magic that was headed by Cygnus Potter. It examined some of the ways in which Muggles have noticed things from the wizarding world.
 * The crop circles Muggle believe are made by extraterrestrials are actually made by wizards and witces competing in the Contorting Cereals contest of the Annual International Wizard Gardening Competition.
 * The UFOs which Muggles spot in the sky are in fact escaped Bludgers.
 * The Loch Ness Monster Muggles claim to have seen is a real animal.