Abstract: An apparatus for exposing a wafer to light. The apparatus includes a light source unit having a light source for emitting light, a first cooling unit for cooling the light source unit, in which the first cooling unit has a gas flowpassage for a gas passing through the light source unit, a second cooling unit for cooling the gas, in which the second cooling unit has a first fluid flowpassage for a first fluid which is to be heat-exchanged with the gas in the gas flowpassage at a position downstream of the light source unit with respect to the flow of the gas, and a first temperature adjusting unit for adjusting the temperature of the first fluid. The first temperature adjusting unit has a second fluid flowpassage for a second fluid which is to be heat-exchanged with the first fluid in the first fluid flowpassage at a position upstream of the cooling unit with respect to the flow of the first fluid.

Abstract: Disclosed is an apparatus for exposing a wafer to light, the apparatus including a light source unit having a light source for emitting light, a first cooling unit for cooling the light source unit, the first cooling unit having a gas flowpassage for a gas passing through the light source unit, and a second cooling unit for cooling the gas, the second cooling unit having a first fluid flowpassage for a first fluid which is to be heat-exchanged with the gas in the gas flowpassage at a position downstream of the light source unit with respect to the flow of the gas.

Abstract: A power monitoring apparatus monitors the voltage fluctuation range of an AC power supply and the duration of voltage fluctuations within the voltage fluctuation range. The power monitoring apparatus looks up a power failure rank table for determining the power failure rank of the power supply on the basis of the voltage fluctuation range and the duration obtained as the monitoring result to determine the power failure rank of the power supply. The power monitoring apparatus sends a power failure signal indicating the power failure rank to a power supply destination of an AC power supply.

Abstract: A power monitoring apparatus monitors the voltage fluctuation range of an AC power supply and the duration of voltage fluctuations within the voltage fluctuation range. The power monitoring apparatus looks up a power failure rank table for determining the power failure rank of the power supply on the basis of the voltage fluctuation range and the duration obtained as the monitoring result to determine the power failure rank of the power supply. The power monitoring apparatus sends a power failure signal indicating the power failure rank to a power supply destination of an AC power supply.

Abstract: A semiconductor manufacturing apparatus for executing an exposure process upon filling a chamber, an illuminating optics unit and a projection optics unit with an inert gas is provided with a supply unit that supplies clean, dry air for raising the concentration of oxygen in a maintenance area, and with a sensor for sensing oxygen concentration or ozone concentration in the maintenance area. When maintenance is carried out, the supply unit is actuated to raise the oxygen concentration in the maintenance area, thereby assuring the safety of workers. A maintenance cover is provided with a door switch for sensing that the cover has been opened. Actuation of the supply unit is started in accordance with the state sensed by the door switch. Alternatively, the supply unit is actuated on the basis of an input ordering the start of a maintenance operation.