RESIN BONDED BODY AND ITS BONDING METHOD

To provide a method for joining resin parts while maintaining precise shape accuracy.SOLUTION: The present invention comprises (a) a preparation process of preparing k parts 1 comprising a thermoplastic resin material 1 and having a plurality of nano-recesses having a size in the nano-numeric range on the junction surface of parts 2 comprising a thermoplastic resin material 2 by processes (b) and (c) below, but having no protrusions protruding to a height of 30 nm or more, and k or k+1 parts 2 comprising the thermoplastic resin material 2 whose glass transition temperature and/or softening temperature is 5 degrees centigrade or more lower than the thermoplastic resin material 1, (b) a contact process in which the parts 1 and 2 are alternately stacked, and (c) a heating and pressing process in which the joint surface of the parts 1 and 2 is pressurized so that contact pressure is generated between...