PURPOSE: To prevent the generation of longitudinal wrinkle on a strip under traveling in a continuous annealing furnace without increasing meandering by forming the entire shape of the roll surface of the furnace to a projecting crown and providing a recessed crown partially in the central part of the crown.

CONSTITUTION: The roll 1 in a continuous annealing furnance is formed as a projecting crown roll in the approximate shape over the entire part of the roll surface thereof. At least one recessed crown 11 is formed partially near the central part of the roll 1. The adequate value of the recessed crown is generally in about 1/2W1/10 range of the projecting crown as a whole. Then, even if conditions such as the width of a plate, tension or the like change, the stable waves are generated in a largest diameter part 12 and the strength thereof becomes extremely weak.