To provide a skin washing agent which is excellent in the foaming speed and the foam creaminess in washing therewith, and which, after washing therewith, is excellent in the moist feeling and the absence of pulling feeling of the skin and does not change the moisture content of skin. A foamable skin washing agent comprising (a) a fatty acid salt, (b) one or more selected from a homopolymer, a dipolymer and a terpolymer derived from a specific cationated monomer (e.g., dimethyldiallylammonium chloride), (c) a polyglyceryl monoalkyl ether, and (d) one or more selected from an acylmethyltaurine salt and a hydroxy ether carboxylate salt.