For almost the past two decades, surface analysis instruments have maintained an UHV environment which is achieved by UHV pumps. Recently, the XHV environment has been required in surface analysis, but an instrument which has many parts in a vacuum is eventually limited in the baking temperature. To achieve an XHV environment in a surface analysis instrument, H2 is the key component. Thus we tested a nonevaporable getter pump to reduce the amount of H2 and we have measured the residual mass spectrum in a practical instrument using a low outgassing rate mass spectrometer. We obtained a low range of 10-9 Pa using the NEG pump and conventional pumps with relatively low baking temperature. The ion source of the sputter-etching gun was mainly the outgassing of H2 under operating conditions, and hence the pumping speed was not sufficient to maintain the amount of H2 from the ion gun.