An optical disc apparatus for performing both the operation of writing data on an optical disc and the operation of reading data that is stored on the optical disc includes a motor for rotating the optical disc, an optical pickup, which irradiates the optical disc with a light beam and detects the light that has been reflected from the optical disc, an evaluation section for obtaining an indicative parameter of the distortion of a signal waveform representing the light reflected from a data stored part on the optical disc while the optical disc is being rotated by the motor, and a control section for changing the number of revolutions of the optical disc Per unit time if a variation in the indicative parameter of the distortion per rotation of the optical disc exceeds a threshold value while the optical disc is being rotated by the motor.