PURPOSE: To provide a soldering method capable of rapidly joining a joining body to a member to be joined with excellent joinability and cleanly finishing a joining point.

CONSTITUTION: An electrode 11 formed of a thin film over the entire surface as the body to be joined is formed uniformly over the entire surface of a crystal vibrating plate 12 of a disk shape and an electrode 13 formed of a thin film to an annular shape are formed at a prescribed width on the rear surface of this crystal vibrating plate 12. A lead wire 14a as the joining body is joined to the electrode 11 formed of the thin film over the entire surface and the electrode 13 formed of the thin film to the annular shape respectively by solder 15 at the respective peripheral edges of the electrode 11 formed of the thin film over the entire surface and the electrode 13 formed of the thin film to the annular shape. The crystal vibrating plate 12 is placed together with the electrode 11 formed of the thin film over the entire surface on a heating plate 16 and after the crystal vibrating plate 12 is heated near to its melting temp., the solder 15 is heated to melt by a solder iron 17, by which the lead wire 14a is joined to the electrode 11 formed of the thin film over the entire surface.