PURPOSE: To produce a soft capsule agent made of gelatin and having high hardness and stability comparable to those of conventional soft capsule agents using oils, by filling an aqueous liquid of sugars having higher concentration than a specific level, as a principal agent.

CONSTITUTION: A soft capsule agent made of gelatin can be produced by filling an aqueous liquid of sugar (e.g. sucrose, glucose, fructose, maltose, etc.) having a concentration of ≥55w/w% as a principal agent. The present soft capsule is characterized by the use of an aqueous liquid in place of oil organic solvent which gives unagreeable feeling when chewed by mistake and is disadvantageous also in view of the production cost. The hardness and stability of the present soft capsule having a sugar concentration of ≥55w/w%, especially ≥65w/w% are comparable to those of the conventional soft capsules produced by using an oil as the solvent of the objective content. An aqueous liquid containing an organic acid or its salt as well as the sugar can also be filled in the capsule. Concrete examples of the content are ascorbic acid, riboflavin, plum pulp extract, etc.