PURPOSE: To prevent the backlash of an image pickup device without increasing the size of said device for a monitor device which monitors a subject by varying the monitoring direction, by providing a brake part that fixes forcibly a support member to a basement and a driving mechanism of the support member.

CONSTITUTION: An image pickup device or a member unified with the pickup device is fixed to a basement 4 through a brake part 8. A driving mechanism 9 drives the part 8 with control. The mechanism 9 is controlled to fix the above- mentioned member to the part 8 when the pickup device has no revolution, and this fixture at the part 8 is released when the pickup device has revolutions. In such way, the backlash of an image pickup device can be prevented without increasing the support mechanism of the pickup device or a field of view controlling mechanism.