Enameling steel sheet highly excellent in unsusceptibility to fishscaling and process for producing the same

The present invention provides a non-aging enameling steel sheet having excellent fishscale resistance characteristics that is suitable for one-coat enameling and a method of producing the same. The enameling steel sheet comprises, in mass%, C: 0.010% or less, Mn: 0.03% to 1.30%, Si: 0.100% or less, Al: 0.010% or less, N: 0.0055% or less, P: 0.035% or less, S: 0.08% or less, O: 0.005% to 0.085%, Nb: 0.055% to 0.250%, and the balance of Fe and unavoidable impurities, in which steel sheet preferably an Fe-Nb-Mn system composite oxide is present, a distribution of Nb mass% concentrations is present in the composite oxide, and the ratio of Nb mass% concentration of a high-concentration portion (Nb max%) to Nb mass% concentration of a low-concentration portion (Nb min%) is Nb max% / Nb min% 1.2.