Film forming method

A film forming method for forming a film on a workpiece, the method comprising:

• a process (A) of providing the workpiece in a treatment container;
• a source gas supply process (B) of supplying a source gas into the treatment container to adsorb the source gas onto the workpiece, and then purging an inside of the treatment container with a first purge gas;
• and
• a reaction gas supply process (C) of supplying a reaction gas into the treatment container after the source gas supply process (B) to oxidize the source gas adsorbed on the workpiece, and then purging the inside of the treatment container with a second purge gas,
• wherein the supply of the source gas in the source gas supply process (B) is one of:
• a process (b1) of supplying a first catalyst gas into the treatment container together with the source gas;
• a process (b2) of supplying a first catalyst gas into the treatment container, then performing purging with a third purge gas, and then supplying the source gas;
• or
• a process (b3) of supplying only the source gas into the treatment container,
• the supply of the reaction gas in the reaction gas supply process (C) is one of:
• a process (c1) of supplying a second catalyst gas into the treatment container together with the reaction gas;
• a process (c2) of supplying a second catalyst gas into the treatment container before supplying the reaction gas, and then performing purging with a fourth purge gas;
• or
• a process (c3) of supplying only the reaction gas into the treatment container,
• the method does not comprise the reaction gas supply process (C) being the process (c3) when the source gas supply process (B) is the process (b3), and
• the first catalyst gas and the second catalyst gas are a same or different types of non-aromatic amine gas.