There are provided a magnetic resonance imaging device and a method of controlling a MRI device. The MRI device includes an RF transmitting coil configured to transmit an RF to an object on a table; an object scanning unit including a position detecting unit configured to detect a position of the object and a thickness detecting unit configured to detect a thickness of the object, and configured to recognize a body shape of the object; and a control unit configured to regulate the RF to be transmitted, thereby compensating an RF field based on the recognized body shape of the object.