The activation of aluminum with low-melting gallium-based alloys makes it possible to obtain a material easily oxidizable by water at room temperature to release similar to 1.2 L of pure hydrogen per 1 g of metal. The kinetics and regularities of the interaction of activated aluminum with water were studied as a function of the amount and composition of metal activators, dispersity of the powder, and temperature. The phase composition of the solid reaction products was shown by X-ray diffraction analysis to depend on temperature and duration of the process.