To provide an intrusion prevention system for preventing a collision accident with a train while permitting invasion of wild animals into a railway site.SOLUTION: The intrusion prevention system 1 comprises an intrusion prevention barrier 10 installed along a railway 5 by providing an entry port 11 at an appropriate position and a beast repellent device 20 for generating a repulsive sound which the beasts dislike. The beast repellent device 20 is installed so that the acoustic wave arrival range 61 of the repulsive sound overlaps the inside of the line site inside the entrance opening 11, and a repulsive sound is generated in a given time period, and outside the given time zone Stop the generation of the repulsive sound.(FIG.【課題】線路敷地内への野生の獣類の侵入を許容しつつ、列車との衝突事故を防止する侵入防止システムを提供する。【解決手段】侵入防止システム1は、適所に侵入口11を設けて線路5に沿って設置された侵入防止バリア10と、獣類が嫌う忌避音を発生する獣類忌避装置20とを備える。獣類忌避装置20は、侵入口11の内側の線路敷地内に忌避音の音波到達範囲61が重なるように設置され、所与の時間帯に忌避音を発生するとともに、所与の時間帯外では忌避音の発生を停止する。【選択図】図1
