PURPOSE: To enable film formation while maintaining a substrate temp. at a low temp. by irradiating the surface of a film under growth with X-rays or electron beams at a low angle, thereby absorbing the X-rays or electron beams into the atoms in the film and exciting the atoms.

CONSTITUTION: The X-rays or electron beams are made incident approximately horizontally (about ≤5°) on the surface of the film formed on the substrate and only the film under growth is irradiated with the X-rays or electron beams to absorb the X-rays or electron beams, by which the atoms in the film are excited and the film is heated. The incident angle of the X-rays or electron beams is so adjusted to be kept within a range of several 10 of the surface. As a result, the film is formable while the substrate temp. is maintained at a low temp. This method is effective for a vacuum vapor deposition method, CVD method, sputtering method and ion plating method all of which do not require a high vacuum.