When a size is increased for mass production, an area of a pressurized surface is increased. This raised a problem in that insufficient load or the like causes a pressure during pressure sintering and a relative density of a thermoelectric conversion element to be likely to become insufficient. As a solution, there is provided a method for producing a thermoelectric conversion element, including: a step of mixing a skutterudite-type thermoelectric conversion material powder containing Sb and a sintering agent containing a compound including Mn and Sb, to obtain a mixture; and a step of sintering the mixture.