FUEL CELL DEVICE AND SECONDARY FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To provide a fuel cell device capable of preventing overheating.SOLUTION: A fuel cell device comprises a fuel cell and a double-wall container for housing the fuel cell. In the space between the double walls of the double-wall container, a contacting member (bimetal 11) is provided, and the state of the contacting member can be changed between a first state, in which it contacts the both of an inner wall 8 and outer wall 9 of the double wall container, and a second state, in which it contacts only one of the inner wall 8 or outer wall 9 of the double-wall container. The heat conductivity between the double walls of the double-wall container is higher in the first state than in the second state.