When a motion in an internal body is analyzed by employing a tomographic image, a relative motion in an internal body is analyzed by moving a viewing point to an arbitrary place. The present invention is composed of: a tomographic image acquisition device 1 for acquiring a tomographic image of a subject targeted for observation; a motion analysis device 2 to which the tomographic image acquisition device 1 is connected, the analysis device performing a motion analysis from the tomographic image obtained by the tomographic image acquisition device 1; and a display device 3 connected to the motion analysis device 2, the display device displaying data outputted by the motion analysis device 2. The motion analysis device 2 includes image processing means 4 for processing the tomographic image obtained by the tomographic image acquisition device 1, point specification means 5 for specifying a plurality of arbitrary points on the tomographic image after image processing by the image processing means 4, viewing point conversion means 6 for converting a motion of a point serving as an observation point to a motion obtained by defining a point other than the observation point as a viewing point from among the plurality of points specified by the point specification means 5, and data output means 7 for outputting data obtained by the viewing point conversion means 6.