To make extension of imaging time as short as possible.

In prescanning A, combinations a₁-a_M of sequences including a navigator sequence NAV and an imaging sequence IS are performed. Then, on the basis of respiration data obtained by the navigator sequence NAV, the range AW of the exhalation end of the respiration of a subject is set. Also, from data segments Seg1-SegM obtained by the prescanning A, the data segment collected when the respiration data is included in the range AW of the exhalation end is specified. In main scanning B, among data segments Seg1-SegN needed for image reconstruction, only the remaining data segments that cannot be obtained in the prescanning A are acquired.