Mass spectrometer

摘要

A mass spectrometer having a resolution improved by introducing ions into a mass spectrometry part (7) with a high efficiency is provided with a small-sized, simple configuration. The mass spectrometer includes an opening/closing mechanism (4) provided between a sample introducing piping part (2, 41) for introducing a sample into the mass spectrometry part (7) and the mass spectrometry part (7) to conduct gas introduction intermittently and control sample passage. The mass spectrometer further includes a pump mechanism (10) to evacuate a high pressure side of the sample introducing piping part (2, 41), that is, an opposite side of the opening/closing mechanism (4) to the mass spectrometry part (7) to have a pressure in a range of 100 to 10,000 Pa.