This invention provides a polymer alloy comprising a polyphenylene sulfide resin and a polyphenylene ether resin. This polymer alloy can eliminate molding whitening which, upon molding, occurs on the surface of the molded product, can impart excellent surface appearance and flame retardance, and further can improve balance between heat resistance and toughness (impact strength) and mechanical strength. The resin composition comprises 45 to 99 parts by weight of a polyphenylene sulfide resin comprising (a) 0 to 96% by weight of a specific linear polyphenylene sulfide resin and (b) 100 to 4% by weight of a specific crosslinking-type polyphenylene sulfide resin. The resin composition further comprises (c) 55 to 1 part by weight of a polyphenylene ether resin. Further, the resin composition comprises (d) 1 to 20 parts by weight, based on 100 parts by weight in total of components (a) to (c), of a styrene copolymer and/or an ethylene copolymer containing any one functional group of glycidyl and oxazolyl groups.