NOVELTY - A hydrogen-producing material composition (2) contains metal material which reacts with water and generates hydrogen, and heat-generating material which are materials other than the metal material, and reacts with water and generates heat, and has mal-distribution portion in which content of the heat-generating material is more than the average content of the heat-generating material included in the whole hydrogen-producing material composition. A heat-generating material (a) is included in portions other than the mal-distribution portion.    USE - Hydrogen-producing material composition is used as fuel source for polymer electrolyte membrane fuel cell used as power supply for personal computer and mobile telephones.    ADVANTAGE - The hydrogen-producing material composition has excellent hydrogen-producing stability.    DETAILED DESCRIPTION - A hydrogen-producing material composition contains a metal material which reacts with water and generates hydrogen, and heat-generating material which are materials other than the metal material, and reacts with water and generates heat, and has mal-distribution portion in which content of the heat-generating material is more than the average content of the heat-generating material included in the whole hydrogen-producing material composition. A heat-generating material (a) is included in portions other than the mal-distribution portion. A heat-generating material (b) which is different from the heat-generating material (a) is included in the mal-distribution portion. The emitted-heat amount generated during reaction between heat-generating material (a) and water is less than 0.5 kJ/g per unit mass of heat-generating material (a). The emitted-heat amount generated during reaction between heat-generating material (b) and water is more than 0.5 kJ/g per unit mass of heat-generating material (b). An INDEPENDENT CLAIM is included for hydrogen-producing apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic structure of hydrogen-producing apparatus.    Container (1)    Hydrogen-producing material composition (2)    Water supply tube (3)    Water supply port (4)    Hydrogen outlet tube (5)