Abstract: A reproducer provided with a vibration value measuring means which has functions of, prior to data reproducing, detecting vibration of, and determining vibration value for, a disc, and which measures a vibration value obtained when the disc with a known mass eccentricity is mounted on the reproducer and is rotated, characterized in that values relating to the measured vibration value are stored in a storage in the reproducer as threshold values indicating allowable limits of the vibration value, thereby preventing unstable vibration detection due to differences between individually manufactured reproducers when a disc with a large mass eccentricity is reproduced at high speed, and permitting a reproducing operation that will not give a user an unpleasant feeling.