A scanning microscope with a light source for illumination of a specimen, a means for spatial spectral division of the detection light, and a detector is disclosed. A metal plate is disposed below the at least one dielectric; and a connecting pin electrically connects the metal plate to the ground electrode and fixes the at least one dielectric and the metal plate to the printed circuit board. The heat-conductingdissipating module includes a substantially cylindrical heat-conducting device having at least one flat portion and at least one heat-dissipating fin mounted on the circumference of the heat-conducting device.