There is disclosed a method for producing a diamond film on a base material by a vapor phase reaction at least with introducing a raw material gas, wherein B(OCH3)3 gas is added to the raw material gas as a source of boron to be doped, and a diamond film is deposited on the base material by a vapor phase reaction utilizing the mixed raw material gas. There can be provided a method enabling easy and uniform production of a diamond film showing a low electric resistivity value with good reproducibility and few problems concerning handling such as serious bad influence on human bodies and explosiveness during the doping process.