A sheet structure obtained by separately producing an artificial leather base material and a leather-like skin, and combining the two together in simple equipment. An artificial leather having air permeability is produced as follows. A film material is filled in concavities of a transfer sheet having a convexo-concave shape reverse to a leather-like convexo-concave surface to form a perforated film layer. On the perforated film layer is formed a porous layer formed of open-cell foam. The porous layer is formed by coating an aqueous polyurethane dispersion solution containing base resin, which is foamed through agitation, followed by drying. The resultant sheet structure is thermally laminated on a desired base material. The base material is composed of a nonwoven fabric, a woven fabric, a knit, or the like, impregnated with foamed polyurethane as necessary. A thermally-fused open-cell foamed layer may additionally be formed on the porous layer to enhance flexibility and peeling strength, Lastly, the transfer sheet is peeled off.