A flame-retardant resin composition comprising (A)(1) a resin component containing an aromatic polycarbonate resin and a styrene-containing resin or (2) a resin component containing a polyphenylene ether resin and a polystyrene, and (B) a flame retardant that is a phosphoric ester of the following formula (I), ##STR1##

wherein each of R1, R2, R3 and R4 is independently an aryl group having 6 to 12 carbon atoms, each of R5 and R6 is independently methyl or a hydrogen atom, each of R7 and R8 is methyl, m1 and m2 are 0 or integers of 1 or 2, each of a, b, c and d is independently 0 or 1, and n is 0 or an integer of 1 or 5.