Thermoelectric conversion device

A thermoelectric conversion device, comprising:

• a base material having a first surface and a second surface that face each other in a thickness direction;
• thermoelectric conversion elements provided in a row in a plane on the first surface side of the base material;
• electrodes, each of which is provided on one end side or other end side of each of the thermoelectric conversion elements in a direction of the row of the thermoelectric conversion elements;
• a heat transfer member disposed on the first surface side of the base material with an interval from at least a part of the thermoelectric conversion elements;
• and
• heat transfer portions, each of which is configured to thermally connect:
• one electrode provided on one side of a hot junction side and a cold junction side of each of the thermoelectric conversion elements;
• and the heat transfer member,
• wherein the base material has recesses on the second surface side, the recesses being provided so as to be recessed in a range of a region which overlaps with interspaces between other electrodes provided on other side of the hot junction side and the cold junction side of each of the thermoelectric conversion elements in a plan view, and
• a low thermal expansion layer having a lower coefficient of thermal expansion than that of the thermoelectric conversion element is provided on a surface side of each of the thermoelectric conversion elements facing the heat transfer member.