PROBLEM TO BE SOLVED: To reduce the burden on an operator during special-light observation.SOLUTION: A D-mirror 32 and a condenser lens 35 are arranged in order on an optical path for a broadband light beam BB emitted from a broadband light source 30 of a light source device 13. A blue LD 31 that emits a blue (B) narrowband light beam Bn toward the D-mirror 32 is provided. A processor device 12 is provided with a part identifying unit 57 for identifying the kind of a part to be observed based on special-light image data obtained by photographing with an electron microscope 11. Based on the identification result of the part identifying unit 57, a CPU 54 of the processor device 12 controls the broadband light source 30 and the blue LD 31 so that the broadband light beam BB and the B-narrowband light beam Bn are emitted at the light quantity ratio predetermined for each kind of part to be observed. Thus, since illuminating light beams can be switched automatically, the burden on the operator can be reduced.
