A film forming method includes forming a film by sequentially performing operations for each of a plurality of kinds of reaction gases, the operations being of storing the reaction gas in a storage part to raise a pressure in the storage part to a first pressure and then discharging the reaction gas into the process vessel, while continuously supplying the counter gas, and purging by repeating multiple times operations of storing a purge gas in the storage part provided in the reaction gas supply passage to raise the pressure in the storage part to a second pressure higher than the first pressure, and discharging the purge gas into the process vessel. A flow rate of the counter gas supplied into the process vessel in the purging is smaller than a flow rate of the counter gas supplied into the process vessel in the forming the film.