Upon detecting a body-motion before starting a main-imaging, a sequence-switching control-unit controls operation so as to switch from a usual-imaging sequence to a body-motion adaptive-sequence corresponding to an imaging-portion of a subject P by referring to a body-motion adaptive-sequence storage-unit. Moreover, upon detecting a body-motion during the main-imaging according to the usual-imaging sequence, the sequence-switching control-unit refers to a collected-data storage-unit, and controls operation so as to perform a retake by switching to the body-motion adaptive-sequence if an already-collected data-volume is less than a predetermined volume. By contrast, if the already-collected data-volume is equal to or more than the predetermined volume at a time of detecting a body-motion during the main-imaging, the sequence-switching control-unit stops the main-imaging, and controls a data-processing unit so as to reconstruct a magnetic resonance image only with collected data.