To provide a wavefront aberration measuring apparatus which can check whether a reference plane for attaching a lens to be inspected and a cover glass are perpendicular to the propagation direction of a light incident thereon or not, even in a period of time when the wavefront aberration is measured.

The apparatus is provided with: a light source for emitting a reference light toward a reference plane plate; a half mirror disposed in the optical path from the light source; a recursive reflector capable of receiving the light which is incident from the side of the light source and which is reflected by the half mirror; a point imaging means for imaging the incident light into a point image and disposed in the optical path of the light which is incident from the side of a spherical mirror and which is reflected by the half mirror and the light which is returned again to the half mirror from the recursive reflector and which is transmitted through the half mirror; and a point image observation means for observing the light which is imaged into the point image by the point imaging means.