To provide a resin composition excellent in impact resistance in severe temperature environments, in which temperature in use is increased or decreased from below zero to high temperature above 100C, such as high-voltage penetration type capacitors or high-voltage relays and peripheral members thereof.

The thermoplastic resin composition comprises, based on (A) 100 pts.wt. of polybutylene terephthalate, (B) 10-60 pts.wt. of block copolymer of terephthalic acid, 1,4-butanediol, and tetramethylene glycol, and (C) 10-50 pts.wt. of ethylene butylacrylate.