To prevent scattering of broken rods to the outside of a drum in a rod mill.

Preventing walls 8 of scattering of broken rods 2a are directly attached to the outer face of the drum 1 at the position of discharge ports 5 of crushed stone of the rotary drum 1, in the form of facing the discharge ports 5. The preventing wall 8 comprises a rising face 8a vertically rising on the outer face of the drum 1 and a tilted face 8b continued to end edge of the rising face 8a in the leaving direction from the outer face of the drum 1. Even if broken rods 2a scatter to the outside of the drum from the discharge ports 5, they collide with the tilted faces 8b of the preventing walls 8 facing the discharge ports 5 and are prevented from further scattering, thus prevented from reaching a hood cover 6 provided at the outside of the preventing walls 8.