To provide an ultrasonograph for measuring the three-dimensional movement of a biomedical tissue in a short time. An image processing section (5) creates volume data from the image data on a B-mode image of a biomedical tissue and creates image data on a series of tomograms in a time series from the volume data in each of two or more cross-section position. A control section (9) allows a display section (81) to display one tomogram in each cross-section position. The user operates an operating section (82) and specifies a measurement image region on the displayed tomogram. A positional variation computing section (61) computes a positional variation in time series of the specified measurement image region in each cross-section position. A movement information computing section (62) computes movement information on the biomedical tissue from the positional variation of the computed measurement image region in each cross-section position.