A crusher comprising: a rotator having a cutter for crushing or chipping a processing object; and a casing for housing the rotator, wherein to a rotating shaft of the rotator, disks (31, 32, and 33) are fixedly fitted at required intervals in an axial direction, a mount portion obliquely cut away with a required angle with respect to a diameter line of the disk is provided at a spot of the disk (31, 32, 33) where the cutter is mounted, a mount base plate is fixedly fitted between the disks (31, 32, and 33) in a manner stretched across the mount portions, the mount base plate is parallel to the rotating shaft and with a mounting face for the cutter having an inclination at a required angle with respect to a cutting motion direction of the cutter, the cutter is fixedly fitted at the mounting face and with an inner face of the cutter inclined at the same angle as the mount base plate with respect to the cutting motion direction, and a relief angle, which is created by a flank and the cutting motion direction, of the cutter is set to 0°, and wherein, on the rear side in the cutting motion direction of the cutter a receiving face provided in a distal end portion of the mount base plate is located on a rear side in the cutting direction of the cutter such that, when the cutter cuts a crushing object while moving, the receiving face of the mount base plate moves along a cut face of the crushing object so as to prevent the crushing object from being drawn in to a side of the cutter, characterized in that the receiving face is structured so as to move along a trajectory of motion of an edge line of the cutter, and wherein an arc plate-shaped jamming preventer is provided on the rear side in the cutting direction of the mount base plate and an arc face-shaped receiving face is structured to move along a trajectory of motion of an edge line of the cutter. a rotator having a cutter for crushing or chipping a processing object; and a casing for housing the rotator, wherein to a rotating shaft of the rotator, disks (31, 32, and 33) are fixedly fitted at required intervals in an axial direction, a mount portion obliquely cut away with a required angle with respect to a diameter line of the disk is provided at a spot of the disk (31, 32, 33) where the cutter is mounted, a mount base plate is fixedly fitted between the disks (31, 32, and 33) in a manner stretched across the mount portions, the mount base plate is parallel to the rotating shaft and with a mounting face for the cutter having an inclination at a required angle with respect to a cutting motion direction of the cutter, the cutter is fixedly fitted at the mounting face and with an inner face of the cutter inclined at the same angle as the mount base plate with respect to the cutting motion direction, and a relief angle, which is created by a flank and the cutting motion direction, of the cutter is set to 0°, and wherein, on the rear side in the cutting motion direction of the cutter a receiving face provided in a distal end portion of the mount base plate is located on a rear side in the cutting direction of the cutter such that, when the cutter cuts a crushing object while moving, the receiving face of the mount base plate moves along a cut face of the crushing object so as to prevent the crushing object from being drawn in to a side of the cutter,