To prevent snaking of a cross rolling mill that rolls the material to be rolled by crossing the central axis of the upper work roll and the lower work roll in the horizontal surface.

A torque detector for the upper work roll and a torque detector for the lower work roll, and from loading torques detected in both torque detectors, a difference of loading torques between the upper work roll and lower work roll is calculated and the cross rolling mill is characterized by a friction coefficient adjusting means which adjusts respective friction coefficients between the material to be rolled and the upper work roll and between the material to be rolled and the lower work roll based on the loading torques' differences.