There are provided a method and device for thermocompression bonding of possibly preventing any warping of a resin member to be caused by thermocompression bonding, and of possibly reducing the time to be taken for processing. The method for thermocompression bonding, includes: preheating a resin member using an infrared radiation section; and subjecting the resin member to thermocompression bonding using a heating section and a pressurization section.