To eliminate pressure regulation of an electrode, to facilitate setting of conditions for fusing and to stably obtain a bonding state with high quality.

A fusing device bonds a lead wire 104 to a terminal 101 of an armature 100. The fusing device is provided with an auxiliary electrode 20 that is electrically connected with the terminal 101 in advance, and a main electrode 10 which is pressed to a hook part 103 of the terminal 101 and supplies current to the auxiliary electrode 20 through the hook part 103. The device is provided with a main electrode driving device 11 moving the main electrode 10 to a pressing direction, a power supply device 30 supplying current between the main electrode 10 and the auxiliary electrode 20, and a controller 40 controlling the main electrode driving device 11 and the power supply device 30. The controller 40 synchronizes the time to supply current to the main electrode 10 with the time to move the main electrode 10 in the pressing direction, and controls the main electrode driving device 11 and the power supply device 30.