A magnetic resonance imaging (MRI) apparatus provides a belt-tension varying unit including a belt winding mechanism that performs reeling and unreeling a belt, a belt driving unit that drives the belt winding mechanism, and belt controlling unit that varies a tension of the belt corresponding to any one of a body length, a body weight, and a part to be imaged of a subject. The belt controlling unit varies the tension of the belt in such a manner that the belt controlling unit makes the tension of the belt large under a circumstance having high possibility where the subject moves, and makes the tension of the belt small under a circumstance having low possibility where the subject moves.