PURPOSE: To prevent the increase of thickness in a mounting section, and to reduce defective soldering while improving reliability by positioning and housing an electronic part at a specified relative position to a part hole by a pedestal and soldering the electronic part to a substrate while being held down by a retaining tool.

CONSTITUTION: An adhesive tape 7 in proper size as a pedestal is stuck onto the rear of a circuit board 1, a chip part 4 is housed so as to be accurately positioned at a required relative position to a part hole 2, the rear of the chip part 4 is fixed by an adhesive tape 7, and the chip part 4 is held at precise position of housing. The stage of the holding is pressed by a press bar 8, cream solder, etc., are injected to connecting sections, hot air from an air heater, etc., not shown is sprayed against the cream solder, etc., and board electrodes and part electrodes 3a and 5a, 3b and 5b corresponding to the board electrodes are soldered 6 to respectively. Accordingly, the unnecessary increase of thickness in a mounting section for the chip part 4 is prevented, and the quantities of solder 6 in each connection section are made proper, thus acquiring appropriate strength and improving reliability.