PURPOSE: To enable a high-output power laser to be operational for many hours by a method wherein a conductive connection between an input transducer driving a Q switch element and a matching circuit is made through a conductive material which covers the whole piezoelectric body and is in planer contact therewith.

CONSTITUTION: A piezoelectric body 2 for an input transducer is provided on one surface of a Q switch medium 1, a gold piece covers the piezoelectric body 2 and is in planar contact therewith, and slant-lined section 4 represents a contact section 4. The gold piece is rendered, at least, larger in area than the piezoelectric body or the electrode section thereof and the edge of the gold piece is so set as to be outside of that of the piezoelectric body 2 without fail. Therefore, there is no singular point on the piezoelectric body so that a contact structure can be obtained in which the concentration of current seldom occurs. By these processes, heat generation, which is caused by electric field, increasing proportionally to the amount of an output power can be restrained to the utmost.