A film forming apparatus comprises: a processing chamber in which a substrate is accommodated; a gas supply configured to supply a gas containing a first monomer and a gas containing a second monomer into the processing chamber; a concentration distribution controller configured to control a gas flow within the processing chamber such that a concentration of a mixed gas including the gas containing the first monomer and the gas containing the second monomer on the substrate has a predetermined distribution; and a temperature distribution controller configured to control a temperature distribution of the substrate such that a temperature of a first region of the substrate is higher than a temperature of a second region of the substrate, the concentration of the mixed gas in a region corresponding to the first region being higher than the concentration of the mixed gas in a region corresponding to the second region.