To provide a means which enables an individual user to set the position of a receiver of a portable telephone system at a more optimum position in person.

A slit 13 for receiver sound hole position movement is formed on the surface of an upper end part of a case 1 horizontally along the upper end part of the case, and a receiver sound hole 4 with a receiver for speech communication arranged therein is configured to be movable horizontally along the slit 13 for receiver sound hole position movement. A slit 12 for moving a receiver movable knob 2 is provided on the top side of the case 1, which is connected to a receiver holder inside the case, the user moves the knob 2 along the slit 12 to thereby be able to move the positions of the receiver and the receiver sound hole 4 along the slit 13 for receiver sound hole position movement so that each user can set the receiver to a position where the user can listen to voice most clearly during speech communication.