PURPOSE: To make attachment/detachment of a platen feasible and also make the whole printer compact by providing a rotary surface wave motor at least at one edge of the platen and giving rotary drive to the platen with the help of the motor.

CONSTITUTION: A surface wave motor 207 has a support member 17 fixed to a frame 4a with an adhesive, etc., an elastic ring 15 and piezo electric element 14 fixed to the external circumferential surface of the elastic ring 15. The internal circumferential surface of the elastic ring 15 is fixed to the right of a platen 1 and the external circumferential surface of a rotary piece 16 formed in truncated cone is pressed by a spring 13. The piezoelectric element 14 oscillates by applying a high frequency voltage to generate a surface wave processing in the circumferential direction of the elastic ring 15. Thus the rotary piece 16 pressed to the elastic ring 15 by the spring 13 rotates in a prearranged direction, giving rotary drive to the platen 1 integrally formed with the rotary piece 16.