Laser scanning microscope

A laser scanning microscope that can construct a fluorescence image with high resolution even with a photodetector having a small array size is provided. A laser scanning microscope includes a line-focusing optical system that focuses laser light from a laser light source in the form of a line; a DMD having a plurality of movable micromirrors that are arrayed in the same direction of the line and reflect the focused laser light; a galvanometer mirror that scans the laser light reflected by the DMD; an irradiation optical system that irradiates a sample with the scanned laser light; a photodetector having a plurality of channels that detect light from the sample and are arrayed in a single line; and a controller that controls the DMD so as to cause the light reflected by the different movable micromirrors to enter the respective channels, and that sequentially switches between the micromirrors that reflect the light that is to enter the channels so that the light from different positions on the sample enters the channels.