To properly align the irradiation optical axis of a laser irradiation optical with a patient's eye to perform a precise treatment.

This ophthalmologic surgical apparatus for irradiating a required portion of the patient's eye with a treatment laser beam to perform the treatment has a laser irradiating means provided with a laser beam source for emitting the treatment laser beam and an irradiation optical system for guiding the treatment laser beam from the laser beam source to irradiate the portion; an eye movement detecting means for detecting a potential difference present between the cornea and the retina and detecting the eye movement of the patient's eye from the result; and an irradiation control means for controlling the laser irradiating means on the basis of the detection result of the eye movement detecting means.