To provide an invader menace repellent device and a method for it capable of preventing a criminal act by an invader.

This invader menace repellent device 10 is provided with a plurality of first sound generation means 16, 18, 20, and 22 simultaneously making a plurality of sounds different in tone and a plurality of second sound generation means 16, 18, 20, and 22 simultaneously making plurality of sounds different in frequency. In this invader menace repellent method, an invader is alerted and repelled when a plurality of sounds different in tone are generated simultaneously from a plurality of first voice sound generation means 16, 18, 20, and 22 and a plurality of sounds different in frequency are generated simultaneously from a plurality of second voice generation means 16, 18, 20, and 22.