A compression apparatus includes at least one compression unit, a voltage applier, an anode end plate provided on an anode separator located at a first end in a direction of stacking, a cathode end plate provided on a cathode separator located at a second end in the direction of stacking, a first seal material that surrounds an outer periphery of the cathode, and a second seal material that surrounds an outer periphery of a first space in which to store compressed hydrogen, the first space being provided between the cathode end plate and the cathode separator located at the second end. The compression apparatus causes, by using the voltage applier to apply a voltage, protons taken out from an anode fluid that is supplied to the anode to move to the cathode via the electrolyte membrane and produces compressed hydrogen. An area of a region surrounded by the second seal material is larger than an area of a region surrounded by the first seal material.