A film forming apparatus performs a film forming process by supplying a plurality of types of reactant gases that react with one another to a substrate in a processing chamber in a vacuum atmosphere. The apparatus includes: a ceiling part provided to face a mounting table and having an inclined surface that is wider gradually from a center toward a periphery; gas supply units provided at a central area of the ceiling part, each of the gas supply units having gas discharge openings formed around a circumferential direction thereof; and a shower head disposed to cover the gas supply units. The shower head has gas supply openings in a bottom portion thereof opposite to the mounting table. An outer periphery of the shower head is located inward of an outer periphery of the substrate mounted on the mounting table.