There is provided a method of forming a polysilicon film, which includes: forming an amorphous silicon film on a substrate; forming a cap layer, which is formed of an amorphous germanium film or an amorphous silicon germanium film, on the amorphous silicon film; forming crystal nuclei of a silicon in the amorphous silicon film by heating the substrate at a first temperature; removing the cap layer after the crystal nuclei are formed; and growing the crystal nuclei by heating the substrate from which the cap layer is removed, at a second temperature equal to or higher than the first temperature.