NOVELTY - Thermoelectric device comprises a closed vessel having an internal space made by metal members and two opposing principal surfaces; an insulating layer (6) formed on the first principal surface; a wiring layer (7,11) provided on the insulating layer surface; thermoelectric elements with one end secured to the wiring layer to stand upright and connected electrically; a metal thin wire net (9) arranged on other ends of the thermoelectric elements to connect the thermoelectric elements (3,3a,3b); and an insulating member provided between the wire net and the second principal surface.    USE - For converting heat into electricity or converting electricity into heat.    ADVANTAGE - Device is capable of improving power generation performance while keeping a hermetic sealing after a heat cycle is applied, and achieves simplification of a structure and improvement in productivity and reliability of the device by reducing the number of articles. A difference of the coefficients of thermal expansions between members constituting the external casing of the device can be reduced. Even when the thermoelectric device is exposed to a high temperature, the joined portion between the metal substrate (2) and lid (4) is not destroyed and the hermetic sealing is never lost.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method of manufacturing a thermoelectric device. Material of a metal member (5) positioned at least on other ends sides of the thermoelectric elements. Out of the metal members is formed of Kovar(RTM: Not defined) and/or stainless steel. A joined portion for connecting metal members provided to constitute a closed structure of the vessel is formed of an alloy of the material of the metal member and nickel. The insulating member is a spray deposited formed of white alumina, gray alumina, magnesia spinel, chromia, or zircon. The metal thin wire net is wrapped up with a metal foil.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of a thermoelectric device.    Substrate (2)    Thermoelectric elements (3,3a,3b)    Lid (4)    Metal member (5)    Insulating layer (6)    Wiring layer (7,11)    Metal thin wire net (9)