Steel sheet for porcelain enameling capable of realizing excellent enamel adhesion with the steel sheet by direct-on enameling once is provided by using a Ti-added steel sheet; there are also a method for producing the same, as well as a porcelain enamel product and the method for producing the same. A steel sheet for porcelain enameling is produced by providing a Ni—Mo alloy plating film on a Ti-added steel sheet containing 0.01% by weight (wherein, % represents “% by weight” hereinafter) or less of C, 0.5% or less of Mn, 0.04% or less of P, 0.04% or less of S, 0.01 to 0.50% of Ti, and balance Fe accompanied by unavoidable impurities, and by then performing heat treatment thereto to control the content of Ni, Mo, and Fe present in the surface of the steel sheet in a predetermined range, porcelain enamel is applied once and fired.