To provide an anti-icing apparatus which is simple in configuration and prevents the icing of an aircraft flying in an icing environment, a wing, the aircraft and an anti-icing method.

The anti-icing apparatus outputs pressure waves toward supercooled waterdrops floating in air present in the direction of the advance of an aircraft 10 to turn the waterdrops into ice by the pressure waves. When the pressure waves give the waterdrops of, for example, the acceleration of 10 G, the pressure of the pressure waves is determined to be 0.9 to 3.3 [Pa] at a given location as the attenuation of the pressure waves is taken into consideration.