PURPOSE: To facilitate easy control and to save labor, by adjusting the projection degree and height of a magnetic head by means of a single screw and an operation of tools from the same direction.

CONSTITUTION: A push screw 9 is turned clockwise and moved downward, and therefore a cone surface 14 pushes the inner fringe of an opening 11 of a substrate 3. Thus the substrate 3 advances to extrude a magnetic head 4 by a prescribed extent, and then a screw 5 is driven tight. Then the screw 9 is turned counterclockwise to move the substrate 3 upward. Thus the surface 14 of a head part 13 is detached from the opening 11, and a flange 12 is fitted to the lower side of the substrate 3 to push up the substrate 3 higher. In such a way, the height of the head 4 can be adjusted. This facilitate easy control for attachment of the head 4 and saves its labor.