A confocal microscope apparatus includes a disk scanner for scanning a specimen with a laser beam, and camera main body for photographing a still image. An exposure time calculation circuit is arranged to generates an exposure time signal for the camera main body. A rotation sensor, a scan track start point/end point determination circuit, and a rotation period calculation circuit are arranged to generate a rotational period signal for the disk scanner. A comparator compares the exposure time signal with the rotational period signal, so that a motor controller and a motor driver control rotation of a motor of the disk scanner by a comparison output from the comparator.