A disk recording or playback device first sets a target region, and a pickup (3) is moved toward the disk inner periphery to turn on a sensor switch SW. The pickup (3) is thereafter reversely moved, and further caused to overrun for a predetermined period of time from the position where the sensor switch is turned off. The pickup (3) is returned after reading the address reached by overrunning. If the address is closer to the disk outer periphery than the target region, the overrun time is decreased, and the movement of the pickup (3) toward the lead-in area is repeated again. When the overrun time becomes not greater than a specified value and if the address then read is closer to the disk outer periphery than the target region, the direction of overrun is reversed toward the disk inner periphery. The overrun time enabling the pickup to reach the target region accurately is saved.