The high cost of artificial diets is the primary factor obstructing the spread of silkworm rearing with artificial diets through the larval stages. To decrease the cost of artificial diets, the nutrition requirements of minerals, lipid and sterol, and vitamin B compounds for grown silkworms (4th and 5th instar larvae) were investigated. Test diets which contained mulberry leaf powder, defatted soybean meal, and corn meal as the main feed ingredients, with varying amounts of minor components (mineral mixture, soybean oil, phytosterol, and vitamin B compounds) were fed to larvae during the 4th and 5th instars. The additive amount of the minor components had no effect on larval development or cocoon production, suggesting the non-essentiality of separate addition of these ingredients. A diet for grown silkworms was developed based on the above results, and the rearing performance of the silkworms fed the diet was satisfactory compared to that of the silkworms fed an ordinary commercial diet.