PURPOSE: To improve the impact resistance over the entire part of a drive and to make the device portable by providing the device with means for absorbing or restraining the motion of a head system during the action of external impact and vibrations.

CONSTITUTION: This magnetic disk device has a stopper 3 which does not impair the function of a head suspension system 4 in an ordinary use state and absorbs and restrains the motion of the head system 5 during the action of the external impact and vibrations in order to decrease the damages on the surface of a disk 2 by a head 5 when the external impact and vibrations act. The stopper 3 for impact resistance is made of a stainless steel SUS 304 and is made into a triangular wedge structure corresponding to a back bone by pressing. A fluororubber material 6 which is a viscoelastic material is stuck to the sub-assembly side. The impact resistant performance at a head disk interface is thereby improved and eventually the impact resistance performance over the entire part of the drive is improved, by which the reliability of the magnetic disk device is improved.