To provide a pulp producing technique which realizes a furniture-sized apparatus for recycling used paper that is capable of being disposed indoor such as small shops.

A pulp producing device includes a beating machine in which a pair of beating discs 41 and 42 are disposed opposite to each other with a close distance and rotatable relative to each other. This beating machine has small beating gaps R (60, 61) between the pair of beating discs 41 and 42 for implementing a sequential beating process comprising at least two steps of a rough beating process and a finishing beating process. The beating gaps R (60, 61) extend from supply mouths 50, 45a formed at a center part of the fixed side beating disc 42 to exhaust mouths 51, 45b formed at a circumferential edge of the beating discs 41, 42. The above configuration enables smooth beating with high processing capability even in an extremely small beating processing space R (60, 61) contained in a space of a furniture-sized apparatus without causing the blockage of used paper.