[Solving Means]A method for joining a plurality of members to be joined composed of metals or materials different in kind from each other which are metal and such an inorganic substance as ceramics to each other, the members being put in a state stacked up and down by having a configuration that a member to be joined 1 is received from an opening of an inside space portion 3 provided in a member to be joined 2 into the inside space portion 3 to be supported by a slope 7 of the inside space portion 3 and the members to be joined 1 and 2 are subjected to a vertical load shown by arrow 14 from a joining tool portion 12 and an anvil 13, while the joining tool portion 12 resonates with acoustic wave vibration or ultrasonic wave vibration transmitted from an acoustic wave vibrator or an ultrasonic wave vibrator to be subjected to vibration in a longitudinal direction shown by arrow 15, so that the members are joined in an ingot-like state, in a diffusion-like state, or in an alloy-like state.