The object of the present invention is to provide a masking member to protect a prescribed part of an article from coating, wherein said masking member has excellent heat resistance and moldability. As for the materials comprising said masking member (11,21,31,41,51), a polymer alloy, containing an engineering plastic, a polyamide, and a compatibilizer is used. In said polymer alloy, the weight ratio of said engineering plastic to said polyamide is set to be in the range of between 20:80 and 80:20, with said compatibilizer being added in an amount of between 0.01 and 50 parts by weight to 100 parts by weight of the sum of said engineering plastic and said polyamide