An apparatus for performing an ophthalmic operation on an eye by photocoagulation using a laser beam while allowing continuous observation of the eye to be treated, includes a light source for producing the laser beam, an observing system having a first inherent optical path including a slit-lamp microscope, a laser optical system having a second inherent optical path, means for transmitting the laser beam from the light source to the laser optical system, means for introducing the laser beam from the second optical path of the laser optical system to the first optical path of the observing system, a contact lens having predetermined characteristics positioned in front of and contacting the eye to be treated, first optical means provided in the first inherent optical path of the observing system for adjusting an objective plane observable from the slit-lamp microscope, means for shifting the objective plane to a desired position along the optical path while observing the objective plane, and second optical means provided in the second inherent optical path of the laser optical system for adjusting a focal point, the laser beam being controlled while adjusting the focal point along the second optical path of the laser optical system, wherein the first optical means controls the movement of the objective plane observed from the observing system according to the predetermined characteristics of the contact lens and the second optical means adjusts the focal point to direct the laser beam on the objective plane.