An apparatus for manufacturing an absorbent body for an absorbent article includes a conveying mechanism for conveying a continuous absorbent sheet, a slitting mechanism configured so that a plurality of slitting blades are pressed against the absorbent sheet conveyed by the conveying mechanism, the slitting blades extending in a predetermined direction, a cutting mechanism for cutting the absorbent sheet against which the slitting blades are pressed and forming the absorbent body, and a stretching mechanism arranged upstream of the cutting mechanism and for stretching, in a direction orthogonal to the predetermined direction, the absorbent sheet against which the slitting blades are pressed, and forming slits in the absorbent sheet.