To provide a process of manufacturing hydrogen gas from cellulose or substances with a high cellulose content which utilizes a mechanochemical treatment in stead of using high pressure vessels and a high temperature treatment at 1,000C.

The process of manufacturing hydrogen gas from biomass comprises weighing a predetermined amount of powdered cellulose or substances with a high cellulose content and powdered calcium hydroxide, putting the weighed substances and a plurality of hard balls in a mixing vessel, mixing and pulverizing the weighed substances for a specific period of time, heating and maintaining the pulverized mixture at a temperature of 350C and 450C and taking out the hydrogen gas generated. Nickel hydroxide may be added to the weighed substances before mixing and pulverizing. The high cellulose substance may be wastes including vegetables, products from vegetables, waste paper, dung, waste foods, construction-related timber wastes or sewage sludge.