To provide methods for generating hydrogen using oral solid preparation containing silicon fine particles or aggregates of the silicon fine particles.SOLUTION: A hydrogen generation method of the present invention comprises a first contacting step of contacting an oral solid preparation which contains silicon fine particles with a crystallite diameter of 1 nm or more to 100 nm or less, or an aggregate of the silicon fine particles and which has hydrogen generating ability, with a first water-containing liquid with a pH of less than 7； and a second contacting step of contacting the silicon fine particles or the aggregates of the silicon fine particles with a second water-containing liquid having a pH value of 7 or more.SELECTED DRAWING: Figure 1【課題】シリコン微細粒子又は該シリコン微細粒子の凝集体を含む経口固形製剤を用いた水素発生方法を提供する。【解決手段】本発明の１つの水素発生方法は、結晶子径が１ｎｍ以上１００ｎｍ以下のシリコン微細粒子又は該シリコン微細粒子の凝集体を含み、且つ水素発生能を有する経口固形製剤を、ｐＨが７未満の第１水含有液に接触させる第１接触工程と、該第１接触工程の後に、該シリコン微細粒子又は該シリコン微細粒子の該凝集体をｐＨ値が７以上の第２水含有液に接触させる第２接触工程と、を含む。【選択図】図１
