Abstract: When a first joining object and a second joining object are joined to each other, the first joining object has a first metal composed of Sn or an alloy containing Sn, the second joining object has a second metal composed of an alloy containing at least one selected from among Ni, Mn, Al and Cr, and Cu. The first joining object and the second joining object are subjected to heat treatment in a state of being in contact with each other to produce an intermetallic compound at an interface between both joining objects such that both joining object are joined to each other. An alloy containing Sn in an amount of 70% by weight or more is used as the first metal. An alloy containing Sn in an amount of 85% by weight or more is used as the first metal.