The introduction of Mn ions into Cu(I)-ZSM-5 was found to lead to an enhancement of the photocatalytic activity for the direct decomposition of N2O into N-2 and O-2 at 298 K. Various in-situ techniques such as ESR, photoluminescence, XAFS as well as a combination of CO-FT-IR and CO-TPD measurements revealed that the accommodation of Mn ions within ZSM-5 zeolite cavities significantly affects the location sites of the ion-exchanged Cu(II) ions as well as the local structure of the Cu(I) ion species formed by evacuation at high temperatures. Moreover, the introduction of Mn ions into ZSM-5 led to an increase in the amount of 3-coordinated Cu(I) species at the main channel of the zeolite, playing a major role as the active species for the photocatalytic decomposition of N2O into N-2 and O-2.