PURPOSE: To enable high reliable wire bonding using covered wire, by installing a nozzle to jet gas via a gas feeding channel, against the intermediate part of a wire protruding from the tip of a bonding tool, and a gas cooling means extending from at least a jetting vent of the nozzle to the gas feeding channel.

CONSTITUTION: Since nitrogen gas 34 is jetted against a prescribed part at the intermediate position of a wire 26 from a nozzle 35, accumulated resin 45 is scattered by the blowing pressure of the nitrogen gas 34. The nitrogen gas 34 jetted from the nozzle 35 is kept cold with high cooling efficiency, by cooling nitrogen gas 42 flowing in a cooling pipe 41 of double-tube structure. Even in the case where the vicinity of the tip of a capillary 24 is turned into a high temperature atmosphere by arc discharge, nitrogen gas 34 of sufficiently low temperature can be jetted, so that the melting amount of coating material 36b never becomes excessive. Thereby, accumulated resin 45 is restrained from ascending up to the inside of the capillary 24, the plugging of the capillary 24 is prevented, and high reliable wire bonding is enabled.