Provided is a novel thermoelectric conversion element with which the thermoelectric power generated in a direction orthogonal to both a temperature gradient and the magnetization can be increased without changing the thermoelectric conversion characteristic of a magnetic material. The present invention is provided with: thermoelectric layer 10 comprising a thermoelectric material exhibiting the Seebeck effect; magnetic body layer 20 stacked on thermoelectric layer 10, said magnetic body layer 20 being conductive and the magnetization or an external magnetic field thereof being oriented in the thickness direction of magnetic body layer 20; low-temperature-side conductor part 44 connecting low-temperature-side end portion 12 of thermoelectric layer 10 and low-temperature-side end portion 22 of magnetic body layer 20; high-temperature-side conductor part 42 connecting high-temperature-side end portion 14 of thermoelectric layer 10 and high-temperature-side end portion 24 of magnetic body layer 20; and output terminals (26a, 26b) for extracting a potential generated in the vector product direction of temperature gradient direction (∇T) of thermoelectric layer 10 and magnetization direction (M) of magnetic body layer 20.