A flip chip mounting method which is applicable to the flip chip mounting of a next-generation LSI and high in productivity and reliability as well as a bump forming method are provided. After a resin 14 containing a solder powder 16 and a gas bubble generating agent is supplied to a space between a circuit board 21 having a plurality of connecting terminals 11 and a semiconductor chip 20 having a plurality of electrode terminals 12, the resin 14 is heated to generate gas bubbles 30 from the gas bubble generating agent contained in the resin 14. The resin 14 is pushed toward the outside of the generated gas bubbles 30 by the growth thereof and self-assembled between the connecting terminals 11 and the electrode terminals 12. By further heating the resin 14 and melting the solder powder 16 contained in the resin 14 self-assembled between the terminals, connectors 22 are formed between the terminals to complete a flip chip mounting body.