PURPOSE: To obtain a high frequency thick film circuit board by using a high purity alumina substrate.

CONSTITUTION: After forming a conductor pattern for a first layer with a first thick film paste 2 having a relatively less PbO content in glass component, a second layer conductor pattern is formed with a second thick film paste 3 having a relatively large PbO content in glass component in such a manner that at least the corners of the first layer conductor pattern can be covered. By doing this, the first thick film paste and the second thick film paste are mixed together during or after the baking, and a conductor pattern having a high adhesion strength with the substrate and being suited to the substrate can be formed, thereby preventing the peeling-off of the conductor pattern and the infusion of glass component.