Provided is an image diagnostic device with which it is possible to correct location misalignment of an image capture subject, and to improve the reliability of the result of the correction, in time series image data. An image diagnostic device is configured of: an input part (13) which receives image data input; a correction unit (14) which computes a correction vector which denotes location misalignment of an image capture subject, and selects image data used with an image correction unit; an image correction part (20) which carries out a correction process on the image data based on the correction vector and creates corrected image data; a control part (21) which controls the correction unit and the image correction part;a memory (22) which stores the corrected image data and measurement data as stored data; an output unit (23) which outputs the stored data externally; a display unit (24) which displays the stored data; and an external input device (30) where an operator makes an input operation