PURPOSE: To minimize the escaping amount of a magnetic head from a magnetic disk by moving the supporting point part of an arm for holding an upper head in the vertical direction with respect to the surface of the magnetic disk without fixing the supporting point part to a carriage.

CONSTITUTION: An arm 5 can be moved up and down by a height-position determining screw 7. At the same time, the arm 5 is always energized upward by a pin 10 and a coil spring 9. The screw 7 is rotated through a rack 12 and a pinion 11, which are interlocked with an inserted floppy disk and moved. When the arm 5 is lowered by a specified amount, the magnetic disk is held by an upper head 2 and a lower head 1 from the both sides. The deflected amount of a plate-shaped spring 6 is converted into the load of the heads. Thus, the heads 1 and 2 follow the movement of the magnetic disk.