To provide a method for producing fertilizer or feed by effectively using garbage by bringing fermentation-based microorganisms to act with the garbage under a condition of insufficient air and fermenting the garbage.

This method for producing fertilizer or feed is to act a complex cultured product of fermentation-based microorganisms to garbage such as waste of vegetables and fishes, ferment the garbage in a condition in which air is insufficient and obtain fertilizer which is ready for use. Dried fertilizer or feed is obtained by drying the fermented product.