Anomalous Nernst effect of epitaxial Fe4N films on MgO(001), MgAl2O4(MAO)(001), and SrTiO3(STO)(001) substrates grown by molecular beam epitaxy was investigated. Moderately large anomalous Nernst coefficients (S-ANE) of 1.4 and 1.7 mu V/K were obtained in the Fe4N films on the MgO(001) and MAO(001) substrates, respectively, and large anomalous Hall angles (similar to 0.06) and transverse thermoelectric conductivities [similar to 1.3 A/(m K)] were derived from the experimental results. On the other hand, a large effective S-ANE of 2.8 mu V/K was obtained in the Fe4N film on the STO(001) substrate. The origin of the enhanced effective SANE is the negatively large Seebeck coefficient (S-SE) in an oxygen deficient STO layer near the surface of the STO substrate. This indicates that it is possible to enhance the effective S-ANE of ferromagnetic materials by utilizing adjacent materials with large vertical bar S-SE vertical bar such as the oxygen deficient STO layer. Published under an exclusive license by AIP Publishing.