PROBLEM TO BE SOLVED: To provide a silent virus inactivating apparatus which transiently and effectively inactivates virus by allowing air to pass through heated space and discharge space between electrodes without catching the virus without pressure loss in a virus inactivation process, and to provide a method thereof and air conditioner using the same.SOLUTION: The apparatus for inactivating the virus floating in the air without catching the virus includes: an air blower 1 for taking the floating virus with the air in an air passage 9 a heating device 2 arranged in the air passage through which the floating virus passes and heating the floating virus a high voltage electrode 3 for performing plasma treatment on the floating virusa ground electrode 4 installed opposite to the high voltage electrodeand a variable high voltage power supply 5 connected for applying a high voltage to the high voltage electrode.
