Abstract: A thermoplastic polyester resin composition is obtained by blending, with respect to (A) 100 parts by weight of a thermoplastic polyester resin, (B) 0.1-50 parts by weight of at least one phosphinate selected from phosphinates and diphosphinates, (C) 0.1-10 parts by weight of a phosphazene compound, (D) 0.1-50 parts by weight of a nitrogen-based flame retardant, (E) 0.1-10 parts by weight of a polyfunctional epoxy compound, and (F) 0.1-20 parts by weight of an olefin resin. The ratio of the parts by weight of component (B) and the parts by weight of component (C) is 2.0-8.0.

Abstract: A liquid crystal polyester resin comprising 42 to 80 mol % of structural unit (I) relative to 100 mol % of the total structural unit of the liquid crystal polyester resin, and ?S (entropy of melting) defined by equation [1] is 0.01×10?3 to 2.7×10?3 J/g·K: ?S(J/g·K)=?Hm(J/g)/Tm(K)??[1] wherein Tm is an endothermic peak temperature determined by: after observation of an endothermic peak temperature (Tm1) observed when heating a liquid crystal polyester under temperature rising conditions of 20° C./minute from room temperature in differential scanning calorimetry, the liquid crystal polyester was maintained at a temperature of Tm1+20° C. for 5 minutes, followed by observation of the endothermic peak temperature observed when the temperature has fallen to room temperature under temperature falling conditions of 20° C./minute and then raised under temperature rising conditions of 20° C.