PURPOSE: To provide a fuel cell in which the clamping pressure of a cell stack can be regulated easily.

CONSTITUTION: A supporting stand 4 is constituted of a fixing stand 6 which is used for fixing an upper clamping bar to a pressure case through a clamping rod 5, and a lower clamping plate 7 which is used for clamping a cell stack 1 used for a fuel cell by pressing the stack 1 upward from its lower side. The plate 7 is connected to a pressure transmission bar 8, which is used for pushing up the plate 7 from the outside of a pressure case 3. The bar 8 is connected to an actuator 10 which converts a pressure fluid, which is supplied from mechanical a pressure-fluid supplier 9 used as a pressure supplying source, into mechanical energy. As a result, the looseness of clamping pressure which is caused due to repetitions of driving and stopping can be regulated easily by controlling the pressure of the pressure fluid supplied from the pressure-fluid supplier 9.