PROBLEM TO BE SOLVED: To provide an invasion prevention structure that can reliably close a gap caused in an installation location of a fence having many irregularities, and can prevent entry of an animal, e.g., to dig up the ground and sneak through.SOLUTION: An invasion prevention structure comprises a fence 1, an animal invasion prevention member 30 driven in the ground F of the installation location of this fence 1 by a predetermined length, and engagement means for mounting the driven animal invasion prevention member 30 to the fence 1. Further, the animal invasion prevention member 30 is integrally provided with: a longitudinal plate 31 driven in the ground F of the installation location of the fence 1 and a horizontal plate 32 bent from the upper end side of this longitudinal plate 31, horizontally extended from this bending portion M and forming a contact surface to be driven.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】凹凸の多い、柵の設置箇所に生じる隙間を確実に閉塞できるとともに、例えば地面を掘り起こして潜り抜けるような動物の侵入をも阻止できる侵入防止構造を提供すること。【解決手段】柵1と、この柵1の設置箇所の地中Fに所定長さ打ち込まれる動物侵入防止部材30と、打ち込まれた前記動物侵入防止部材30を前記柵1に取り付ける係着手段とを含み、さらに、前記動物侵入防止部材30は、柵1の設置箇所の地中Fに打ち込まれる縦板31と、この縦板31の上端側から折り曲げられ、この折り曲げ部分Mから水平に延設された打ち込みのための当たり面部を形成する横板32とを一体に備えた動物侵入防止杭からなる。【選択図】図1