The present invention provides a thermoelectric conversion element module and a manufacturing method thereof capable of easily realizing a high-density array and securing connection reliability. The module includes a thermoelectric conversion element group made up of P-type elements and N-type elements alternately arranged in a first direction and a heat-resistant insulating member filling the periphery of the thermoelectric conversion materials, wherein the P-type elements and the N-type elements are connected via connection electrodes on a side portion of the group along the first direction, and connection electrodes at other parts of the group along a second direction crossing the first direction. The module is manufactured by forming a connection electrode layer that extends to the side portion of the group on the surface of the group and cutting this connection electrode layer between the thermoelectric conversion elements along the first direction and the second direction.