For the purpose of preventing development of motion artifacts and improving image quality, a first displacement N1 of the diaphragm before a scanning section 2 performs an imaging sequence and a second displacement N2 of the diaphragm after the scanning section 2 has performed the imaging sequence are detected by a body motion detecting section 25 as displacement caused by respiratory motion of a subject. Thereafter, based on the first displacement N1 and second displacement N2 of the diaphragm detected by the body motion detecting section 25, imaging data is selected as raw data by a raw data selecting section 26. Then, based on the imaging data selected as raw data by the raw data selecting section 26, a slice image of the subject is produced by an image producing section 31.