To provide an ultrasonic bonding apparatus which can fix to a horn by a sufficient fixing force while it is a small and simple bonding tool fixing part and in which a bending vibration or the like is not excited for the bonding tool.

The other main surface of a component P in which a bump P1 is formed on one main surface thereof is adsorbed by an adsorption surface 35 of the bonding tool 30. A pressing force and an ultrasonic vibration are applied to the component P through the bonding tool 30 from a horn 10, and a bump P1 is bonded to the surface B to be bonded. A shaft 32 is formed in the back surface side of the absorption surface of the bonding tool 30. An attachment hole 23 which engages and holds the shaft 32 and a threaded hole 24 which intersects perpendicularly to this attachment hole are formed by intersecting perpendicularly with the hole 10 to the surface B to be bonded. A clamping screw 25 is engaged with the threaded hole 24, and the shaft 32 is pressed and fixed to the attachment hole 23.