In the wig 10 provided with a wig base 11 and hair materials 12 attached to the wig base, the wig base 11 is zoned in its front portion 11a to an artificial skin portion 110a from a virtual hairline of the wearer's forehead portion toward a top portion and to a net pattern 11b connected thereto, the artificial skin portion is made of a synthetic resin film integrated with a shape retention net, provided with a front edge region 111 of the pre-determined width from a front edge 11a′ positioned on the wearer's virtual hairline toward inside and with a rear region 112 connected to the front edge region, and the front edge region 111 is bent to a sharper inclination than the wearer's corresponding head outline, giving a curved ridge line, resulting in an arc-shaped warp up prevention structure.