Film forming method and article manufacturing method

A film forming method comprising:

• an arranging step of arranging a curable composition on a base material;
• a contact step of bringing the curable composition into contact with a film forming region of a mold after the arranging step;
• a curing step of curing the curable composition after the contact step;
• and
• a separation step of separating the curable composition and the mold after the curing step,
• wherein in the contact step, a gas that fills a space between the base material and the mold exists, and
• in a case where a solubility coefficient of the gas to the curable composition is defined as S [kg/m3·atm], a diffusion coefficient as D [m2/s], and an average liquid film thickness that is a value obtained by dividing a volume of the curable composition by an area of the film forming region as T [nm], S·D·T is not less than 1.75×10−9, and S is not more than 10.