A laser-annealing method includes the steps of a first step of cleaning a
non-monocrystal silicon film formed on a substrate, and a second step of
laser-annealing the non-monocrystal silicon film in an atmosphere
containing oxygen therein, wherein the first and second steps are
conducted continuously without being exposed to the air. Also, a
laser-annealing device includes a cleaning chamber, and a laser
irradiation chamber, wherein a substrate to be processed is transported
between the cleaning chamber and the laser irradiation chamber without
being exposed to the air.