The invention relates to a humidifier for 
fuel cells and a fuel 
cell stack with the humidifier. The humidifier is formed by overlaying multiple humidifying units and humidifying membrane assemblies; each humidifying unit is formed by successively overlaying a dry panel, one humidifying membrane 
assembly and a wet panel, and one humidifying membrane 
assembly is arranged between two humidifying units in a clamping manner; each humidifying membrane 
assembly, each dry panel and each wet panel all are provided with three inlets and three outlets, and each dry panel and each wet panel both are provided with an air 
branch inlet and an air 
branch outlet; and the fuel 
cell comprises successively connected front-end plate, humidifier, rear-end plate, 
cell stack and bottom plate, and the front-end plate, the rear-end plate and the cell stack are all provided with three inlets and three outlets, wherein the three inlets and the three outlets comprise a master 
hydrogen inlet, a master air inlet, a master water inlet, a master 
hydrogen outlet, a master air outlet and a master water outlet. Compared with the prior art, the humidifier for 
fuel cells has the advantages of being capable of effectively humidifying air, improving service life, simplifying installation program, improving efficiency, reducing cost and the like.