Method for producing bonded body

A method for producing a joined body obtained by joining a base material A, a solid joining agent containing an amorphous thermoplastic resin, which is at least one of a thermoplastic epoxy resin and a phenoxy resin, as a main component, and a base material B in this order,

• wherein
• at least the base material A is a thermoplastic resin base material,
• an epoxy equivalent of the amorphous thermoplastic resin is 1,600 g/eq. or more or the amorphous thermoplastic resin does not contain an epoxy group, and a heat of fusion of the amorphous thermoplastic resin is 15 J/g or less, and
• wherein the method comprises:
• a joining step (2-1) of joining at least one of the base material A and the base material B to the solid joining agent in a state in which a temperature of the joining surface of at least one of the base materials and the solid joining agent is raised to the melting point thereof or higher;
• and
• a joining step (2-2) of joining the base material A and the base material B by pressurizing the base material A and the base material B via the solid joining agent in a state in which a temperature of the joining surface of at least one of the base material A and the base material B is raised to the softening point thereof or higher.