NOVELTY - The hydrogen generator comprises a reactor containing hydride in solid form, an orifice (27) for evacuating the hydrogen product, a water-releasing unit (24) for the hydrolysis reaction, and an envelope (23) to isolate the hydride. The hydrogen is generated by hydrolyzing a hydride (22). The envelope is made up of consumable material. The envelope is adapted to contact water and the hydride in a site capable of- serving as reaction site for hydrolysis and moving in the reactor as the material constituting the envelope, which is consumed by the hydrolysis reaction of products.    USE - Useful for generating hydrogen by hydrolyzing a hydride.    ADVANTAGE - The generator is simple and compact, and ensures fast and effective generation of hydrogen with high yield. The generator continuously produces the hydrogen without pollution.    DETAILED DESCRIPTION - The hydrogen generator comprises a reactor containing hydride in solid form, an orifice (27) for evacuating the hydrogen product, a water-releasing unit (24) for the hydrolysis reaction, and an envelope (23) to isolate the hydride. The hydrogen is generated by hydrolyzing a hydride (22). The envelope is made up of consumable material. The envelope is adapted to contact water and the hydride in a site capable of- serving as reaction site for hydrolysis and moving in the reactor as the material constituting the envelope, which is consumed by the hydrolysis reaction of products. The material constituting the envelope is a metallic material corroding in a presence of a basic medium, an organic material degrading itself in the presence of the basic medium, and an aluminum/alloy of aluminum dissolving under hydrolysis reaction of products to produce hydrogen. A catalyst is introduced into the reactor in a salt form, which is dissolved in water or in a form of solid particles, which is distributed in the hydride. An opening in the reactor coincides with a pipe (21), which is formed by the envelope to convey the water within the reactor. The envelope is covered by a sheath made up of a dispersible but water insoluble material. A unit constituted by the sheath and the envelope is immersed in water. The envelope is in a cylindrical/cone shape with circular/polygonal base in which the envelope has an elongated and hollow pipe. The envelopes have a similar/dissimilar geometry distributed in the reactor. An INDEPENDENT CLAIM is included for a fuel cell.    DESCRIPTION OF DRAWING(S) - The diagram shows the hydrogen generator:    Pipe; (21)    Hydride; (22)    Envelope; (23)    Water releasing unit; (24)    Orifice. (27)