PURPOSE: To execute an operation for transferring display data to a recorder 19, and transferring and inputting it from the recorder without suspending a scan, in the ultrasonic diagnostic device.

CONSTITUTION: The objective device is provided with a recorder 19 and a display memory 12 which can execute a data transfer. Also, the device is provided with a display memory write control 11 for inhibiting write to a display memory 12 executed by a read-out control selection superposing circuit 10 at the time of data transfer and at the time data of reproducing display. Moreover, the device is provided with a display control circuit for displaying the output of the read-out control selection superposing circuit on a CRT 16 at the time of regular scan and at the time of data transfer, and displaying the output of the display memory 12 on the CRT 16 at the time of data reproducing display.