To provide the method of manufacturing an antenna substrate, capable of eliminating the need of the formation of a through-hole to the substrate and the formation of a relay circuit and manufacturing a tag using a simple process at a low cost.

In this method of manufacturing the antenna substrate 1 for which a semiconductor chip 3 is mounted and an antenna circuit pattern 2 is formed, a connection pad 10 electrically connected with a semiconductor chip electrode is formed near the semiconductor chip 3, and the connection pad 10 and the antenna circuit pattern 2 are electrically connected by forcibly fitting a U-shaped conductive metal piece 11 for which insertion needle parts 11a are formed at both ends to the connection pad 10 and the outer peripheral side end part 5 of the antenna circuit pattern 2. After forcibly fitting the insertion needle parts 11a of the conductive metal piece 11, by bending or caulking the projected ends of the insertion needle parts 11a at the connection pad 10 and the outer peripheral side end part 5 of the antenna circuit pattern 2, the conductive metal piece 11 can be conducted to the connection pad 10 and the outer peripheral side end part 5 of the antenna circuit pattern 2.