An information recording/reproducing apparatus includes a focusing optical system for focusing light from a light source on an information recording medium as a light spot and an error signal generation system for generating an error signal that represents the positional deviation between an information track and the light spot on the information recording medium from the light reflected by the information recording medium. The apparatus further includes a tilt measurement system for measuring the amount of relative inclination between the focusing optical system and the information recording medium and an offset application system for performing off-track of the light spot by applying an electric offset corresponding to the measured amount of inclination to the error signal. Since the electric offset that corresponds to the amount of inclination is added directly to the error signal, the apparatus does not require a complicated algorithm and can improve the recording and reproduction characteristics easily at low cost.