A magneto-optical disk apparatus performs at least one of recording and reproduction of information on or from a magneto-optical recording medium having a disk shape. The apparatus is provided with an optical device including an objective lens, for irradiating the medium with a light beam, and a first magnetic field applying device for applying a magnetic field modulated according to information to a portion on the medium which is irradiated with the light beam. The first magnetic field applying device includes a magnetic head for generating a magnetic field and a floating-type slider for supporting the magnetic head. The apparatus further includes a second magnetic field applying device for applying to the irradiated portion on the medium a constant magnetic field an orientation of which is inclined with respect to the optical axis of the objective lens, and a moving device for moving the first and second magnetic field applying devices and the optical device together in a radial direction of the medium.