Abstract: A bump forming method comprising a first step of forming a ball (5) at a distal end of a wire (4) which protrudes from a lower end of a capillary (12); a second step of opening a damper (11) which securely holds the wire (4) above the capillary (12) and bringing down the capillary (12) as well as the damper (11), in which an amount of movement of the damper (11) is smaller than that of the capillary (12) by such an amount as to be equivalent to a length of the wire (4) being protruded from the lower end of the capillary (12) in the first step; a third step of forming a bump (21) from the ball (5) by bonding; and a fourth step of separating the wire (4) from the bump (21) by closing the damper (11) and lifting up the damper (11) and the capillary (21) to an initial position of the first step as well as causing a distal end of the wire (4) to protrude from the lower end of the capillary (12) by a predetermined length, whereby a step of drawing out a leading end of the wire (4) from the capillary (12) is elimina