Method of manufacturing pulp and paper

An object of the present invention is to provide a technique for producing superior quality regenerated pulp with downsized and energy saving recycled pulp manufacturing equipment. The present invention, the pulp slurry solids concentrations that include the used paper pulp is 1.5 wt% or more, the long fiber fraction with outward-type slit screen having an opening of the slit width of 0.1mm~0.3mm min and comprising classifying the short fiber fraction, a process for the preparation of regenerated pulp, solid content ratio of the long fiber fraction and a short fiber fraction is 10: 90 to 60: a 40, the long fiber fraction the above method the difference in Canadian standard freeness of the short fiber fraction is 100ml~300ml is provided.