A secondary-neutral mass spectrometer has been developed which combines postionization by means of an electron gas (plasma) with a high-transmission magnetic mass spectrometer and a finely focused ion beam produced in a Ga liquid-metal ion source. The instrument can be operated in a large-area direct bombardment-mode extracting the sputtering beam out of the plasma, or in a microprobe mode utilizing the focused Ga+ ion beam to effect sputtering. In the former case secondary-neutral intensities of up to 10(9) c/s can be realized; together with the high abundance sensitivity those translate in a detection limit in the few-ppb range. In the microprobe mode, secondary-neutral micrographs have been recorded using a focused 20 keV Ga+ beam with a spot size of less than or similar 1 mum and a current of some nA. From these data an elemental detection sensitivity of 10(-3) is inferred, necessitating image acquisition times of the order of 2500 s.