A magneto-optical disk is provided with a recording layer that exhibits perpendicular magnetization, an intermediate layer wherein in-plane magnetization occurs at room temperature and a transition from the in-plane magnetization to perpendicular magnetization occurs as the temperature thereof rises, and an auxiliary layer that is made of a rare-earth-transition-metal alloy and that exhibits perpendicular magnetization, and these layers are laminated in this order. The composition of the rare-earth-transition-metal alloy is set so that the magnetic moment of the rare-earth metal is relatively greater than that of the transition metal at room temperature and the compensation temperature is located between room temperature and the Curie temperature T.sub.c3. A magneto-optical recording apparatus for rewriting information on the magneto-optical disk is provided with a single magnet for applying H.sub.w onto a portion on the magneto-optical disk irradiated by a light beam, as well as for applying H.sub.init having a greater intensity than H.sub.w onto a portion that is apart from the portion irradiated by the light beam. This arrangement makes it possible to achieve a more compact, thinner magneto-optical recording apparatus which allows light-modulation overwriting.