A microscope of the present invention causes laser light emanating from a light source to enter an optical fiber via a laser light introducing mechanism. The exit end of the optical fiber is connected with an adapter having a fiber position adjustment knob. The back focal position of an objective lens and the exit end position of the optical fiber are made conjugate by a condenser lens provided inside a reflecting illumination projecting tube. By shifting the exit end position of the optical fiber, conventional reflecting illumination and evanescent illumination are available.