To obtain a styrenic resin composition having high flame resistance without causing dripping of thermally degraded molten material when burning.

This styrene resin composition includes (a) 10-40wt.% organic halogen-based compound as a flame retardant, (b) 2-10 pts.wt. ammonium polyphosphate-based compound and/or phosphate of a triazine compound and (c) 0.05-8 pts.wt. of a agent for preventing dripping (polytetrafluoroethylene or a chlorinated polyethylene) in 100 pts.wt. styrenic resin.