To provide an organic fertilizer using mainly animal excreta, particularly cow dung as a main raw material, promptly composted and having reduced malodor in the manufacturing step and high phosphorus content and further capable of preventing continuous cropping injury, giving disease resistance to plants, increasing crop yield and culturing large flowers and fruits and a method of manufacturing the same.

The method of manufacturing the organic fertilizer comprises: an excreta pretreatment step of mixing the excreta with plant based raw materials to control the hardness of the excreta; a primary fermentation step of piling the excreta after the excreta pretreatment step and partially degrading and fermenting; a secondary fermentation step of adding rice bran and a culture solution for microorganisms into the excreta after the fermentation step; and a tertiary fermentation step of adding a microorganisms degraded material to the excreta after the secondary fermentation step to additionally ferment.