PURPOSE: To provide a locking mechanism which consumes less electric power by decreasing the space of this locking mechanism to assure locking.

CONSTITUTION: This disk device has a magnetic head and coil 4, not shown in Fig., via a pivot arm 2 around a pivot bearing 1. A solenoid 12 having a plunger 11, the axial center of which is parallel with the pivot bearing 1, is mounted to the pivot arm 2 between the pivot bearing 1 and the coil 4. A yoke 5a of a voice coil motor 3 is provided with a locking hole 13 with a taper 23a into which the plunger 11 intrudes in correspondence to the case where the magnetic head exists in a shipping zone. Synthetic resin films having a small coefft. of friction are preferably formed in the locking hole 13 and on the taper 13a. The above-mentioned solenoid 12 is made into a two-way latch type having electromagnetic coils above and below and having a permanent magnet therebetween.