The present invention enables the formation of a wide absorbent body without an increase in production cost or the occurrence of poor crushing or thickness unevenness. A plurality of crushers (2, 3) are disposed in a mutually offset fashion in the axial direction (B) of a rotating blade (3a). The fluff pulp for crusher (2) is introduced into an upstream duct (5a), and the fluff pulp from crusher (3) is introduced into an upstream duct (5b). The fluff pulp air-conveyed through the upstream ducts (5a, 5b) flows together within a downstream duct (6), and is air-conveyed towards a rotating, fiber-stacking drum (7).