One of an electrode terminal of an electronic component and a connecting terminal of a wiring substrate is provided with solder beforehand, one of the wiring substrate and the electronic component is secured, and the electrode terminal and the connecting terminal are made to abut each other so that one of the wiring substrate and the electronic component, whichever is not secured, is held. The electronic component is heated so that the solder melts, and the solder is solidified while the electronic component is held, so that the electrode terminal and the connecting terminal are bonded to each other by the solder. Further, while an interval formed between the wiring substrate and the electronic component by the melted solder is being held, the electrode terminal and the connecting terminal are finely moved relative to each other with reference to a surface of the wiring substrate in an XYθ direction.