Stishovite synthesized from natural basalt showed the highest concentration of hydrogen ever reported. The water concentration obtained from the polished single crystal of stishovite in this study was up to a maximum of 5628 ± 291 atoms of hydrogen per 106 silicon atoms (844 ± 44 ppm water). The concentration of hydrogen increased with increasing substitution of trivalent cations, which is almost aluminum, and temperature has a significant effect on the incorporation of hydrogen into stishovite. The result of this study suggests that stishovite in subducted basaltic crust could be an important water‐containing phase and contribute to the transport of hydrogen to the lower mantle.