| 摘要 |
In a vacuum-exhaust device, a pair of first and second on-off valves (121, 122) are provided in series between a vacuum chamber (101) and an oil-rotary vacuum pump (110). A vacuometer (140) for measuring a vacuum degree is provided between the pair of first and second on-off valves (121, 122). After storing a vacuum degree of the vacuum chamber (101) measured with the first on-off valve (121) being open, the controller closes the first on-off valve (121) and opens the second on-off valve (122) to obtain a vacuum degree in the vicinity of the oil-rotary vacuum pump (110). Then, the controller opens the first on-off valve (121) and the second on-off valve (122), so that the vacuum chamber (101) is evacuated by the driving of the oil-rotary vacuum pump (110). With this arrangement, while oil, oil vapor and the like from the oil-rotary vacuum pump (110) can be prevented from flowing into the vacuum chamber (101), the vacuum degree can be measured with the single vacuometer (140). |
