This invention concerns detergents composed of hollow spherical pellets which have various advantages such as small apparent specific gravity, moderate congeability even at a high temperature and humidity, uniformity in diameter, and extremely high mechanical strength as well as high water solubility, which are obtained by pelletizing a detergent composition being in a plastic state, and containing mainly sodium silicate, surface active agent(s), water, and inorganic builders, followed by thermally drying and foaming said composition. Further, this invention provides an effective process for manufacturing such detergents.