The present invention provides a thermoelectric conversion material having a reduced thermal conductivity and having an improved figure of merit, and a method for producing the material. The thermoelectric conversion material has, as formed on a resin substrate having recesses, a thermoelectric semiconductor layer formed of a thermoelectric semiconductor material, wherein the resin substrate comprises one formed by curing a resin layer of a curable resin composition. The production method for the thermoelectric conversion material comprises a resin substrate formation step of transcribing a protruding structure from an original plate having the protruding structure onto a resin layer of a curable resin composition and curing the layer, and a film formation step of forming a thermoelectric semiconductor layer of a thermoelectric semiconductor material on the resin substrate.