PURPOSE: To remove the flaws on the surface of a billet safely by using a stationary-type flaw removing machine and by setting roller tables in a movable state to follow up the bend or zigzag shape of the billet.

CONSTITUTION: A stationary-type flaw removing machine whose main body 2 is a heavyweight machine weighing more than 15W16 tons is adopted. Both lightweight moving roller tables 3, 4 are supported by the flaw removing machine so that they can move round to follow up the bend or zigzag shape of a billet 1. According to this arrangement, the structure for followup of a bend or zigzag shape of the billet 1 can be small-sized and simple. At the same time, when flaw-removing operation is executed at high speed, both moving roller tables 3, 4 can follow the bend or zigzag shape of the billet 1 effectively and flaw removing operation can be carried out safely.