A device for mass spectrometry in continuous operation can be equipped with a focused electron beam source or laser radiation source. It can further include a vacuum chamber, a stage for placing the specimen, and an ion beam column with a plasma source for producing a primary ion beam and a secondary ion mass spectrometer for secondary ion analysis. The ion beam column is connected to an inert gas source and to a reactive gas source and is modified for simultaneous introduction of at least two gases from the inert gas source and reactive gas source. The secondary ion mass spectrometer is of an orthogonal Time-of-Flight type to ensure the function with the ion beam column in continuous operation.