This invention relates to an apparatus for detecting magneto-optical anisotropy which can be utilized as an information reproduction apparatus for detecting information recorded on a magnetic medium. The apparatus consists of a light source (10), a magneto-optically anisotropic medium (20), a polarization analyzer (33A) and a light detector (34). To avoid the information reproduction by means of the linearly polarized light as in the prior art, the apparatus of the present invention reproduces the information using the light source (10) which generates the elliptically polarized light. This makes it possible to reproduce the information having a high signal-to-noise ratio.