This slit blade block includes multiple comb teeth adjacent to multiple outer blade pieces. Each comb tooth has a leading end surface, and a protruding part protruding in a direction away from the outer blade pieces. The protruding parts include an apical part that is the outermost end in said direction away from the outer blade pieces. The leading end surfaces of the protruding parts are positioned between the leading end surfaces and the base end surfaces of the adjacent outer blade pieces. Length L1 in the height direction, defined by the apical part of the protruding parts and the leading end surfaces of the protruding parts, is less than or equal to thickness L2 of the outer blade pieces, defined by the leading end surface and the base end surface of the outer blade pieces.