[Problem] To provide a film-forming agent for cosmetics, which can form a film having excellent water resistance and excellent sebum resistance while also having high washability, and a cosmetic containing this film-forming agent for cosmetics.[Solution] A film-forming agent for cosmetics, which contains a copolymer polymerized from a monomer composition containing (A) an unsaturated monomer having at least one polysiloxane structure in the molecule and (B) an unsaturated monomer having at least one acidic group or salt thereof in the molecule, wherein the content of the monomer (A) is at least 30 wt% with reference to the monomer composition.
