PURPOSE: To perform high grade processing for both uses as the data for MTI display and B-mode display, by providing a plurality of individual memory means in which complex echo data is written in a temporary memory means at every scanning.

CONSTITUTION: In B-mode display processing, the square average value of the complex data stored in the constitutional memories of a bipolar video file to constitute a unipolar video and the average value of the data at the same position of (m) memories is calculated. In MTI processing, the complex data of the constitutional memories are subjected to band-pass or high-pass processing in a time t-axis direction to erase the data from a stationary object and only changing data of a moving body is outputted. The brightness data of B-mode display stored in a B-mode data file 11 and the data having a color attribute from the brightness data file 12a, hue data file 12b and saturation data file 12c of an MTI data file 12 are read from a television format and converted to three primary color data of RGB by a color encoder 13 and said three primary color data are converted to an analogue signal by a DA converter 14 to be displayed on a CRT.