PURPOSE: To attain high speed seeking to required information from a large capacity optical disk without revising the rotational speed of the optical disk by highly densely recording the data larger than storage capacity of a standard disk recorded at a constant linear velocity in a high density disk at a constant angular velocity.

CONSTITUTION: A control part 8 supplies a constant for rotating the high density disk D1 at a required angular velocity to a spindle servo 2. The servo 2 calculates the angular velocity from the inputted constant, and controls a motor 1 so that the disk D1 is rotated at the angular velocity. The motor 1 rotates the disk D1. An FG pulse p1 corresponding to the angular velocity of the motor 1 is inputted to a data source 3, an encoder 4 and a head moving motor 7, and the FG pulse p2 is inputted to the servo 2. The servo 2 compares an incorporated reference signal with the required angular velocity, and controls the motor 1 to the required angular velocity. The required data are outputted from the data source 3 synchronizing with the pulse p1, and are inputted to a recording head 6 through the encoder 4 and a CO-DA encoder 5, and the motor 7 is moved from the inner periphery to the outer periphery of the disk D1 synchronizing with the pulse p1, and the data are recorded.