An etching method for etching a silicon-containing film formed in a substrate by supplying an etching gas to the substrate is provided. The method includes supplying an amine gas to the substrate, in which the silicon-containing film, a porous film, and a non-etching target film that is a film not to be etched but is etchable by the etching gas are sequentially formed adjacent to each other, so that amine is adsorbed onto walls of pores of the porous film. The method further includes supplying the etching gas for etching the silicon-containing film to the substrate in which the amine is adsorbed onto the walls of the pores of the porous film.