A laser processing device comprising: an optical system having a laser beam source, and an air-tight chamber provided separately from the optical system, wherein the chamber has a transparent portion for transmitting a laser beam emitted from the laser beam source, on a light-receptive face thereof receiving the laser beam, the chamber is capable of accommodating a donor substrate on which an organic substance layer including at least a luminous layer to be transferred is formed and an acceptor substrate onto which the organic substance layer is transferred from the donor substrate by the laser beam transmitted through the transparent portion, and the inside of the air-tight chamber is in an inert gas atmosphere or in a vacuum atmosphere.