AJ Abdallah, who was 36, was discovered by a business colleague at the Detroit studio on Tuesday.
It is thought he had been dead for at least two days.
Eminem recorded The Slim Shady LP at the studio in 1997. Since it was released in 1999, it has sold more than five million copies.
Police suggested that a robbery may also have taken place at the studio, saying that some equipment used there was missing.