PURPOSE: To clear up the causes of abnormality generation by image-picking up, inputting and electronically recording the picture of a monitoring subject area with a television camera when it is detected that an object invades the monitoring subject area.

CONSTITUTION: A sensor part 1 composed of an ultrasonic wave transmitting and receiving device intermittently emits an ultrasonic signal to the monitoring subject area and measures a time until the reception of a reflected wave. Then, the intrusion of the object is detected. For a television camera part 2, automatic focusing control is executed with a prescribed period under the control of a focusing distance detecting part 7. A system control part 5 and a stroboscope control part 3 are activated by such a detecting output and the picture of the monitoring subject area is image-picked up and inputted by the television camera part 2. This image-picked up and inputted picture is temporarily stored in a picture memory 4 with receiving the control of the system control part 5 and after that, transferred to a picture recording part 6. Then, the picture is electronically recorded and kept.