A self-consistent kinetic model was developed in order to study the production of active species in Ar-O2 surface-wave microwave plasmas with a relatively small N2 addition. It is shown that the Ar-O2-N2 mixture produces efficiently the same active species as an Ar-O2 discharge, including oxygen atoms, metastable O2(a1∆g) molecules and the VUV emitting Ar(4s) states. Furthermore, active N-containing species are additionally produced, in particular N atoms and NO ground-state and excited molecules, which makes the ternary mixture very interesting for numerous plasma applications.