Abstract: A method for manufacturing a tank for storing hydrogen in metal hydride powder comprising a closed enclosure divided into closed elementary cells (1) defined by walls (2, 3, 4, 5), each of the cells (1) containing metal hydride powder (6), characterized in that each of the cells (1) is manufactured successively by carrying out the following steps: certain of the walls defining it are assembled in order to form an open cavity or alveolar cell, and then one or more massive pieces (7) of a material capable of forming a metal hydride are placed in said cavity, and then the last walls of the cell (1) are assembled in order to close the latter; the aforementioned steps are repeated for manufacturing all the cells (1) of the enclosure, and then the enclosure is closed, hydrogen is introduced into the enclosure for transforming the massive piece(s) (7) into the metal hydride powder (6).