A thermoelectric conversion element includes: a magnetic layer; a conductive film formed on the magnetic layer and configured to generate an electromotive force in an in-plane direction by inverse spin-Hall effect; and two terminal sections formed to contact with the conductive film at two portions whose potentials are different to each other by the electromotive force. Each of the two terminal sections contacts with the conductive film in a continuous or discrete contact surface. A longitudinal direction of a minimum rectangle which encompasses the continuous or discrete contact surface of each of the two terminal sections intersects with the direction of the electromotive force.