The present invention provides a production method of a printed circuit board having a circuit pattern with a little variation in the thickness at a low cost without a special step for removal of a dummy pattern. The present invention is characterized in that an insulating layer 2 is formed in a given pattern on one surface of a supporting substrate 1, a circuit pattern 6 is formed on the insulating layer 2 while forming a dummy pattern 7 in an area free of the insulating layer 2 on the one surface of the supporting substrate 1, and an unnecessary part of the supporting substrate 1, which is free of the insulating layer 2 and the circuit pattern 6, is removed by dissolution together with the dummy pattern 7.