An event signal is generated in response to a specific event as a trigger. A recording control unit controls the operation of an image recording unit on the basis of the event signal, thereby automatically forming, as a unit, and recording moving image information based on a unified standard. In addition, an event signal is generated in response to a specific event as a trigger. On the basis of ultrasonic image data of a frame corresponding to the event signal generation, a representative image as an index for search is automatically generated and recorded in association with the ultrasonic image data of the corresponding frame. Furthermore, the recorded representative image is read out and set on the screen. The ultrasonic image data is reproduced on the basis of the frame associated with the representative image selected by the operator.