The present invention provides a vacuum apparatus that includes a plurality of vacuum containers each having a gas inlet and an exhaust outlet, a gas supply system for introducing a desired gas into each of the vacuum containers through the gas inlet, and an exhaust system for keeping each of the vacuum containers at a low pressure. In this vacuum apparatus, the exhaust system includes a plurality of multistage vacuum pumps connected in series. The exhaust outlet pressure of the last-stage vacuum pump is substantially at atmospheric pressure. The last-stage vacuum pump is designed to exhaust gas from a plurality of vacuum pumps at previous stages.