Abstract: Information on the side of the body of an exposure apparatus is effectively used on the side of the laser light source apparatus. There is provided a laser light source apparatus which supplies a laser beam to a body of an exposure apparatus which exposes a wafer, and includes a controller adjusting an operation condition of the laser light source apparatus based on exposure information about the exposure operation supplied from the body of the exposure apparatus. The exposure information is exemplified by information on the waiting time until the light emission start or light emission continuation time and the operation condition is exemplified by the gas pressure in an emission chamber in which a laser beam is emitted, the temperature in the emission chamber and a number of revolutions of a blower in the emission chamber.

Abstract: A laser apparatus includes a laser element that emits the laser beam. A detector detects the laser beam emitted from the laser element. A controller controls the laser element such that the laser beam is oscillated subject to multiple conditions, such as the emission frequency and the energy of the laser beam, when the laser element is in a ready state, based on the detection results. In the ready state, the laser beam is not emitted from the apparatus onto a subject. Closely monitoring the oscillated beam in the ready state allows the precise beam desired to be emitted in an operational mode. The apparatus is useful for fabricating semiconductor devices.