In this paper we show mass spectrometry results for a radio-frequency-driven micro-atmospheric pressure plasma jet (mu-APPJ) discharge obtained using a mass analyzer with triple differential pumping allowing us to sample directly in ambient atmospheric pressure environment (Hiden HPR-60). The flow of the buffer gas (mixture of helium and 1% oxygen) was 2 slm and 3 slm and the excitation frequency was 13.56 MHz. We monitored production of atomic oxygen and nitrogen in the plasma for different flows and powers given by the RF power supply. These measurements were made for energies of electrons emitted from the ionization filament below the threshold for dissociation of O-2 and N-2. In addition to oxygen and nitrogen atoms, yields for O-2, N-2, NO and O-3 are recorded for different powers and gas flows. It is shown that the mu-APPJ is symmetrical and operates in alpha-mode. The power transmitted to the discharge was below 5W in all measurements.