A laser processing apparatus provides a heating chamber, a chamber for laser light irradiation and a robot arm, wherein a temperature of a substrate on which a silicon film to be irradiated with laser light is formed is heated to 450 to 750 DEG C. in the heating chamber followed by irradiating the silicon film with laser light so that a silicon film having a single crystal or a silicon film that can be regarded as the single crystal can be obtained.
