A hydrogen generator comprises a container for storing a hydrogen generating material including a metallic material for generating hydrogen by the exothermic reaction with water. The container comprises a water supply pipe for supplying water into the container and a hydrogen outlet for discharging the hydrogen generated in the container to the outside of the container. The hydrogen generator is characterized in that, when the wall surface of the container which faces the hydrogen outlet is taken as a reference plane, a water supply port at the end of the water supply pipe disposed in the container is disposed near the reference plane, the water supply pipe includes a vertical portion extending from near the center of the reference plane in the direction vertical to the reference plane, and a water absorbent is disposed on the outer periphery of the vertical portion of the water supply pipe and not disposed in the portion of 15% or longer of the effective length of the vertical portion on the hydrogen outlet side.
