The present invention provides a novel method for producing a laminate to be used as a light-transmissive electrode layer and an N-type semiconductor layer of a wet or solid-state dye-sensitized solar cell comprising a light-transmissive electrode layer, an N-type semiconductor layer, a P-type semiconductor layer, and a facing electrode in this order. In said method, a member to be used as the light-transmissive electrode layer is cathode-polarized in a treatment solution containing a Ti component so as to form a titanium oxide layer to be used as the N-type semiconductor layer on said member.