NOVELTY - The anaerobic digester comprises a digestion tank for storing a mixture of an organic mixture and an anaerobe and manifoldly forming an injection nozzle that is connected to an outlet port of the carrier path, an injection pipe for spraying the mixture within the digestion tank transferred through the carrier path, a reservoir having a space for receiving the mixture and an anaerobic digestion process is performed within the reservoir, an inlet port injecting the organic mixture into an inner portion of the reservoir, and a canonical vent for ejecting the mixture to outside.    USE - The anaerobic digester is useful in a biogas production equipment for producing biogas (claimed) from an organic mixture including sewage of food, agricultural and stockbreeding products.    ADVANTAGE - The digester has improved anaerobic digestion efficiency by activating the agitation reaction of the organic mixture.    DETAILED DESCRIPTION - The anaerobic digester comprises a digestion tank for storing a mixture of an organic mixture and an anaerobe and manifoldly forming an injection nozzle that is connected to an outlet port of the carrier path, an injection pipe for spraying the mixture within the digestion tank transferred through the carrier path, a reservoir having a space for receiving the mixture and an anaerobic digestion process is performed within the reservoir, an inlet port injecting the organic mixture into an inner portion of the reservoir, a canonical vent including an outlet port for ejecting the mixture to outside, a mixer stirring the mixture within the digestion tank, a gas exhaust port for ejecting a biogas generated within a the reservoir, and a filtering unit filtering the biogas. An upper inflow hole and a bottom intake are arranged in different heights of the reservoir. A microorganism feeder is installed on the carrier path and supplies the anaerobe through the carrier path. A mixed liquor suspended solid (MLSS) measurement device is installed on the carrier path and measures the concentration of the MLSS of the mixture within the digestion tank. A buffer tank additionally ferments an acid fermenter. The digester removes a precipitating material remains in the reservoir. An emergency vent discharges the mixture within the digestion tank in an emergency situation. The injection nozzle automatically measures a surface angle of a surface of the mixture within the digestion tank, where an injecting angle of the injection nozzle is controllable. An INDEPENDENT CLAIM is included for a biogas production equipment.