Line beam light source, line beam irradiation device, and laser lift off method

A line beam irradiation apparatus (1000) includes a work stage (200), a line beam source (100) for irradiating a work (300) placed on the work stage (200) with a line beam; and a transporting device (250) for moving at least one of the work stage (200) and the line beam source (100) such that an irradiation position of the line beam on the work moves in a direction transverse to the line beam. The line beam source includes a plurality of semiconductor laser devices and a support for supporting the plurality of semiconductor laser devices. The plurality of semiconductor laser devices are arranged along a same line extending in a fast axis direction, and the laser light emitted from emission regions of respective ones of the semiconductor laser devices diverge parallel to the same line to form the line beam.