| 摘要 |
PROBLEM TO BE SOLVED: To optimally use a maximally large number of pumps from an economical viewpoint and a technical viewpoint, and to maximally similarly distribute a generating gas load to a plurality of maximally simple and resembled or similar pumps so as not to have reaction to a process.SOLUTION: A pump system is provided for discharging gas from a plurality of chambers 1 and 2 having at least three vacuum pumps. When at least two pre-pumps 5 and 6 and at least one turbo molecular pump 3 are provided, at least one cross-section reducing part 9 for adjusting and/or reducing a gas flow, is arranged in at least one connecting pipe 8 between at least the two pre-pumps 5 and 6. |
