1. An image analysis device comprising a computer configured to operate as: a first calculating part that calculates a magnitude of motion of an image element from time-series images of pulsating myocardial cells; a second calculating part that calculates a feature quantity based on the magnitude of the motion of the image element calculated by the first calculating part; and an identifying part that identifies whether the image element is a predetermined image element based on the feature quantity calculated by the second calculating part, wherein the second calculating part calculates the feature quantity based on a comparison between magnitudes of motions of image elements in images of two time zones which are temporally successive among the time-series images.