A fuel tank produced in such a manner that an upper shell and a lower shell melt-molded as two split molded parts from a PPS resin composition are welded to each other at a welding portion. The PPS resin composition contains (a) 60% by weight to 95% by weight of a PPS resin, and (b) 5% by weight to 40% by weight of an olefin resin. The (a) PPS resin contains (a-1) a PPS resin having an MFR of 90 g/10 min to 350 g/10 min and an amount of extracts by chloroform of 2.2% by weight to 4.5% by weight. The (b) olefin resin contains (b-1) a specific olefin copolymer, and (b-2) an ethylene-.alpha.-olefin copolymer. The MFR of the PPS resin composition is 15 g/10 min to 50 g/10 min.