(Cu1−xAgx)2O oxide films with cuprite structure are presented. The p-type film demonstrates an exceptional increase in hole cconcentration up to 1.18 × 1021 cm−3 with increasing Ag to 33 at.%. It is revealed from high-resolution transmission electron microscopy along with X-ray diffraction analysis that the oxide remains a single phase with the Ag content up to 33 at.%. Raman spectroscopy measurements exhibit different symmetrical features for the oxide than those of Cu2O. This suggests that the valence-band edge level can be raised as a result of the incorporation of Ag1+ into Cu2O, which is verified by the small acceptor ionization energy observed for the (Cu0.67Ag0.33)2O. In addition, the coexistence of Cu1+ and Ag1+ is shown to suppress variable-range-hopping conduction, demonstrating weakly degenerate semiconductor behavior.