A video signal selector (18) has a selector switch (60) for selectively outputting one of an endoscopic video signal and an ultrasonic video signal, and a selector control circuit (62) for controlling the selector switch. The selector switch selects the endoscopic video signal by default. The selector control circuit switches the selector switch to the ultrasonic video signal in response to input of an ultrasonic image capture command for commanding to save an ultrasonic image (48).