A polypropylene-based resin composition including (A) 70 to 96 mass % of a polypropylene-based soft resin having an ISO D hardness of 35 or less and containing 25 to 55 mass % of xylene-insoluble part at room temperature and 75 to 45 mass % of xylene-soluble part at room temperature, (B) 2 to 10 mass % of homopolypropylene having a melt mass flow rate (MFR) at 230° C. under a load of 2.16 kg measured in accordance with JIS K 7210 of 1 to 30 g/10 min. and stereoregularity (meso pentad fraction) of 90% or more, (C) 2 to 20 mass % of a propylene-ethylene random copolymer having an ethylene content of 1 to 10 mass %, and (D) 0 to 15 mass % of a platy inorganic filler.