This manufacturing method for an absorbing body comprises: a first step that is a step of sequentially introducing an absorbent fiber aggregate and a water-absorbent resin into a gap that is formed between a first face and a second face and that is smaller than the thickness of the absorbent fiber aggregate, wherein irregularities are formed on at least one of the first face and the second face； a second step of applying a shearing force on the absorbent fiber aggregate and mixing the absorbent fiber aggregate and the water-absorbent resin by moving the first face in parallel relative to the second face； and a third step of layering the mixed absorbent fiber aggregate and water-absorbent resin by dropping and drawing same into a concave portion with a prescribed shape.
