To provide a scanning microscope capable of deflecting a beam at a high speed without using an acoustooptical element.

The scanning microscope employs a micromirror array (2) as a device for deflecting the beam in a frequency scanning direction, and a linear image sensor (16) is used as a photodetector. All the micromirrors in the micromirror array (2) are rotated in the same direction with nearly the same frequency. The cost of the digital micromirror is lower than that of the acoustooptical element and the observation conditions can be easily set, so that the device cost of the scanning microscope can be lowered. Besides, since the linear image sensor is provided with a charge storage capacity, it has an advantage that image failures are prevented even in the case some micromirrors are deviated from the prescribed rotating speed.