PURPOSE: To make the whole subject device thin structive and to improve the reliability of a head carriage by providing a position regulating means for abutting a shutter and regulating its height.

CONSTITUTION: By setting the height H of a shutter regulating post 1b to be approximately the same as the height of a cassette positioning post 1a, a projection of the shutter from the lower surface of a cassette 31 due to backlash and opening of the shutter can accurately be regulated, and in view of a design, it is not necessary to set in advance an extra gap for the purpose of absorbing an error of the shutter in shape, so that a gap A' between the head carriage 3 and the shutter 31c can extremely be diminished. By this method, the whole body is reduced in thickness, while the reliability of the device is improved.