To provide a lightweight solid formed member capable of being formed by using waste soil which is discharged from a water purification plant and the effective utilization of which is difficult, or pumice existing in a large amount in the natural world, and also being used as a member of a shaped object that requires lightening of the weight, such as covering for gardening, block fence or pillar and to provide its forming process.

The forming process of this solid formed member, comprises mixing and agitating waste soil, sawdust, a water-soluble adhesive and water together to obtain a mixture, and filling a forming mold with the mixture and thereafter drying and hardening the mixture, to form it into a formed member having a prescribed shape. Alternatively, the forming process of this solid formed member, comprises mixing an agitating pumice, sawdust, a water-soluble adhesive, water and gypsum together to obtain a mixture, and filling a forming mold with the mixture and thereafter, drying and hardening the mixture, to form it into a formed member having a prescribed shape.