a magnetic disk unit has a magnetic head - disk stickiness eliminating mechanism suitable for a small - sized , low power consumption type magnetic disk unit of a high recording density . the magnetic disk unit has a housing in which is enclosed a magnetic disk medium made of glass , a spindle and a spindle motor for driving the magnetic medium in rotation , a slider for supporting a magnetic head and an actuator for positioning the magnetic head . an impact force applying mechanism mounted adjacent the housing applies an impact force to the housing for manually imposing a predetermined certain impact force on the housing . by applying an impact force manually to the housing before use of the magnetic disk unit or when the disk unit becomes inoperative due to sticking , it is possible to easily eliminate the sticking phenomenon between the magnetic head and the magnetic disk medium , thus permitting operation of the magnetic disk unit .