Scanning operation of acquiring data by repeating a scan based on the same encoding pattern at least once by using an R wave occurring at time T0 as a trigger is executed with respect to all encoding patterns. The necessary number of data for image reconstruction are extracted from MR data acquired by temporally retrospecting from the R wave occurrence time (time T1) next to the R wave (time T0) used as the trigger on the basis of the obtained data, data acquisition time information, and the R wave time. The extracted data are then rearranged to generate a data set for imaging the movement of the heart which is associated with end-diastole after the occurrence of the R wave used as the trigger, thereby performing image reconstruction.