A method of producing a printed wiring board (3) comprising a mounting recess portion (1) for mounting an electronic part, a conductor pattern (7), and a heat-sink plate (6) arranged at the bottom of the mounting recess portion (1), characterized in that a conductor pattern (7) is formed on an insulating substrate (5);
a heat-sink plate (6) is adhered to a lower face of a portion of the insulating substrate (5) forming the mounting recess portion; and
a laser beam (2) is irradiated to an upper face of the portion (10) forming the mounting recess portion to form a mounting recess portion (1).