A method of detecting oxygen or air, in a vacuum processing device and air leakage determination method

A method of detecting oxygen or air, in a vacuum processing chamber, comprising: Providing a grid (102), a Ionenauffangers (103) and a filament (101), in which an oxide is formed on a metal surface; Applying a filament current to the filament (101), said thermionic electrons, which are generated by heat generation of the filament (101) may be discharged, whereby the to the filament (101) flowing filament current is controlled so that an emission current flowing through the emitted thermionic electrons arriving at the grating (102) is generated, is constant, the output thermionic electrons an undetermined type of gas that is present in the vacuum processing chamber, (due to collision with gas molecules of the gas before arriving at the grid ionize 102), said positive ions are generated; Trapping the ions with the Ionenauffanger (103); and Measuring a value of the filament current and detecting whether existing in the vacuum processing chamber gas is oxygen or air, based on the measured value, the pressure in the vacuum processing chamber 5 × 10