The present invention provides a confocal scanning microscope whereby fluorescence observations can be made using a plurality of types of excitation light without the need for attaching and detaching a light source to and from the optical fiber. The confocal scanning microscope comprises: a light source unit for emitting excitation light that excites a sample; a scanner unit for scanning the sample with the excitation light; and an imaging camera for capturing an image of the sample by receiving fluorescent light emitted from the sample; the light source unit having a plurality of light sources for emitting laser light with different wavelengths and a multicore optical fiber cable for transmitting light from the plurality of light sources, one end of the multicore optical fiber cable being separated into a plurality of optical fibers, and light from each of the plurality of light sources being input to one end of each of the separate optical fibers.