An artificial hair and a wig using the same are provided which have such feeling as appearance, tactile and texture and preferable physical properties similar to natural hair, wherein an artificial hair 1 has a sheath and core structure comprising a core portion 1B and a sheath portion 1A covering said core portion 1B, and by making the core portion 1B of a polyamide resin, especially a semi-aromatic polyamide resin, and the sheath portion 1A of a polyamide resin having a rigidity for bending lower than the core portion 1B, especially a linear saturated aliphatic polyamide resin, the rigidity for bending, for example, can be made to have a value close to that of natural hair, and further its variation behavior depending upon humidity can be controlled quite similar to natural hair, thereby the wig made of it as a material has natural feeling, so that the wig having an excellent appearance can be offered.