To provide a bellows pump capable of being used as a hydrogen pump, successively sucking without actually causing pulsation, and successively discharging with constant flow rate and pressure.

The bellows pump is equipped with a plurality of bellows sucking/discharging fluid by expanding/contracting. When one bellows sucks the fluid, the other bellows is structured to discharge the fluid, and the total fluid sucking amount and discharge amount of the plurality of the bellows is made to be uniform.