A device for fusing and fixing a transferred toner of a predetermined image onto a print paper is provided. In particular, a fusing device which can instantly control induced current provided to a fusing unit in an image printing apparatus which heats the fusing unit using the induced current is provided. The fusing device includes a fusing unit which is resistance heated or induction heated by an induced current, and fuses the toner onto the print paper using the generated heat. A sensing unit senses the temperature of the fusing unit. A reference current generating unit generates a predetermined reference current to heat the fusing unit to reach a predetermined temperature based on the temperature of the sensed fusing unit and the reference temperature. A pulse width modulation signal generating unit generates a pulse width modulation signal for generating the induced current so that the induced current corresponding to the reference current is supplied to the fusing unit.