To provide a spherical solid material and its manufacturing method where sand can be easily solidified to be spherical small stones using an existing manufacturing facility and not using a mold.

Viscous soil, sand and a solidifying material are housed in a rotation body and water is added in it while rotating. The viscous soil is granular and has a mean particle diameter of 5 mm or less and is favorable to contain an alunite, an amorphous silicate and an A type zeolite as auxiliary components produced in the production step of activated clay or a zeolite. The solidifying material is powdery and favorable to contain a water-absorbing hardening accelerator containing baked kaolin or talc, a hydraulic solidification material containing hemihydrate gypsum or light burned magnesia, an auxiliary hardening material containing baked siliceous sand and an aggregation accelerator containing an anion-based polyacrylamide.