Problem to be Solved To make it possible to simplify an image alignment process and shorten time therefor. Solution Characteristics are: performing a process for alignment between an ultrasound image (a US image) generated on the basis of a reflected echo signal of a cross-section plane of a diagnosing object received with an ultrasound probe and a reference image (an R image) obtained by another image diagnostic apparatus to display the images on a display screen 22 of an image displaying section； storing a plurality of results of the alignment process together with alignment data and capture images 20； displaying the stored capture images 20 on the display screen 22 as a list； and, when one of the displayed capture images 20 is selected, performing the alignment process by the alignment data corresponding to a capture image 20 to which a selection mark 21 is attached.
