Abstract: A high-quality magneto-optic signal is obtained by setting an optimum phase condition at the time of reproducing the land or groove record in a magneto-optic recording medium. By adjusting the angle of inclination of a wavelength plate, an optimum amount of phase compensation is provided to the land or the groove. Furthermore, the inclination of the wavelength plate is made variable, and the DC component of the magneto-optic signal is used as an adjusting signal in order to effect a phase compensation. In reproducing the signals recorded in the land and/or groove, an optimum amount of phase compensation is provided in each case, whereby a best producing condition is obtained, and high-density records can be realized.