To prevent a part to be examined or an object to be examined from receiving bad influence due to the unnecessary irradiation of light by eliminating the complexity of operating the ON-OFF of an illuminating switch when a doctor being an examining person illuminates and magnify-observes the part to be examined and the object to be examined taken out from the patient at the time of the medical operation of opthalmology and otolaryngology.

A proximity switch 3 ON/OFF-controlling the flickering of the light source of illuminating light transmitted through a light guide 4 corresponding to the approach/separation of an observer is provided at a part of the microscope for medical operation A so as to oppose the observer. Then the light source is turned on or off by the approach of the observer to an eye piece part 2 to illuminate the part to be examined and the light source is turned off by the separation of the user to the part 2.