The present invention relates to an anaerobic digestion apparatus for solid manure, in which water is infiltrated into solid livestock manure through a screen wall inside an anaerobic digester to soften the solid manure, dilute toxic substances generated during the anaerobic digestion process, and enhance the buffering capacity, thereby improving biogas production efficiency and enabling stable operation when anaerobically digesting solid livestock manure. In addition, a funnel-shaped slope is provided at the lower portion of the anaerobic digester so that residual digestate can be easily discharged upon completion of anaerobic digestion.

More specifically, the apparatus comprises: a screen wall in which the solid manure of livestock, crushed by a crushing device, is stored, the screen wall being formed in a polygonal or circular shape in plan view and having its wall formed as a mesh structure; a main body formed at a predetermined distance outside the screen wall, the main body having a leachate outlet and a solid manure discharge unit at its lower portion and a cover formed at its upper portion; a heating element provided on the inner wall surface of the main body to heat the leachate between the inner wall of the main body and the screen wall; a plurality of injection ports formed on the outer wall surface of the main body, through which air or water compressed and supplied from a compressor is sprayed onto the screen wall to prevent the screen wall from becoming clogged; a water inlet formed in the upper cover of the main body to introduce external water into the interior of the main body; and a gas outlet formed in the upper cover of the main body to discharge gas generated from the solid manure inside the main body.