A defibration processing device is capable of efficient defibration in a multiple stage rotating part, and a fibrous feedstock recycling device. The defibration processing device has a first rotating part disposed on a side into which defibration feedstock flows, and a second rotating part disposed on a side to which defibrated material defibrated in the first rotating part is discharged. The first rotating part and second rotating part each have on the axis of rotation side thereof a base, and a protruding part protruding from the base in a direction away from the axis of rotation. A spacer is between the first rotating part and second rotating part. An external restriction plate protrudes from the stationary part side toward the spacer, and an internal restriction plate protrudes from the axis of rotation side of the first rotating part and second rotating part toward the stationary part.