PROBLEM TO BE SOLVED: To provide a defibrating device capable of uniformly defibrating a raw material sheet, ensuring the flow passage of air between cutter plates and preventing a defibrating roll from overheat and the like.SOLUTION: A defibrating device 10 making a fibrous material by pulverizing a raw material sheet includes: a plurality of cutter plates 13； a defibrating roll 12 rotated and driven in one direction； and a raw material sheet supply mechanism 16 introducing the raw material sheet 31A to the outer peripheral surface of the defibrating roll 12. The cutter plates 13 are provided with a plurality of rotary blades 13a arranged in the circumferential direction of a periphery and plate parts 13b supporting the rotary blades 13a. The length of the rotary blades 13a in the axial length direction X of the defibrating roll 12 is formed so as to be longer than that of the plate parts 13b and continuous spaces 17 are formed over the whole circumference in the circumferential direction Y of the defibrating roll between plate parts 13b, 13b of adjacent cutter plates.SELECTED DRAWING: Figure 4
