The present invention relates to a digester stirrer installed in the digester, the central axis for a cylindrical support provided on the center of the digester, wherein a cylindrical support center to center of rotation to the axis round for rotating the pipe-shaped pipe, a plurality of impellers disposed in the rotating pipe the support is installed on the central axis support plate provided at the upper end, the upper side above the support plate for the central axis fixing portion, and the lower end of the rotation pipe to secure the drive unit, the bottom surface of the support the digester a central axis lower for rotating the rotary pipe to provide the rotating pipe seated digester including a stirrer for seating. Digester stirrer installed in the digester and the digester of the present invention has a high stirring efficiency was lower shaft vibration occurs. Thus, it is capable of ensuring the structural stability as well as, in digester constructions of an existing fire extinguishing gas and a pump agitation system separate structural reinforcement It provides the advantage that you can easily install without.