The Ministry of Magic is the government for witches and wizards. The head of the Ministry is Cornelius Fudge. Some of the departments are The Misuse of Muggle Artifacts where Mr. Weasley is in charge, The Magic Reversal Squad, The Improper Use of Magic Office, and Governors of the Magical Schools.

When Voldemort was at power, the Ministry of Magic had a tough time rounding up all the Death Eaters that worked for Voldemort. Only wizards or witches can work in it, not muggles, for obvious reasons. A lot of people at the Ministry of Magic have been shady characters. Barty Crouch, who was killed by his own son, was working there. Draco Malfoy's father, Lucius Malfoy, also worked there. He bribed all the governers to vote to suspend Professor Dumbledore.

Another terrible thing he did was put Tom Riddle's diary inside of Ginny Weasley's book. Even though it lead to the whole plot of the Chamber of Secrets, it almost killed Ginny. One other thing I neglected to mention is that Percy Weasley, "Mr. Perfect" of the Weasley household, also works there. He started out as Crouch's assistant. When Crouch was assassinated, Percy took over his job. Mr. Crouch calls Percy, Weatherby. So if you see Percy, call him Weatherby.