The invention provides a porous film including a polylactic acid based resin (A), a thermoplastic resin (B) that is not a polylactic acid based resin, and a filler (C), wherein resin (A) and resin (B) account for 10 to 95 mass% and 5 to 90 mass%, respectively, of the sum total 100 mass% of resin (A) and resin (B), while the filler (C) accounts for 1 to 400 parts by mass of the sum total 100 parts by mass of resin (A) and resin (B), with the porosity being 1 to 80%. The present invention provides a polylactic acid based porous film that has high flexibility, moisture permeability, heat resistance, and bleed-out resistance.