PURPOSE: To attain stable recording and reproduction while interrupting a vertical action and a resonance action by locking a vertical movement mechanism driving a disk table at a prescribed height.

CONSTITUTION: When an elevation motor is driven, an elevation block 6 is slid in a vertical direction along motor guide shafts 7, 7. When the elevation block 6 and a spindle motor 3 reach the prescribed position during the upward action, the upper horizontal plate 258a of a leaf spring 258 is fitted into a projecting part 6b, and the force for shifting the elevation block 6 to the side of chassis 2 is interrupted. When the elevation motor continues the rotation further, the upper horizontal plate 258a of the leaf spring 258 is separated off from the projecting part 6a of elevation block 6 since the leaf spring 258 is pressed in the direction A by the pin 257, then the downward movement is started. Thus, spindle motor 3 is locked to the prescribed height in the loading state, thereby the stable signal is read out and written in.