PURPOSE: To grind rolls having roll surfaces different in roughness with the same rotary grinding wheel.

CONSTITUTION: The binding strength of abrasive grains of a rotary grinding wheel 40 is made smaller at both side sections 42 than at the center section 41 in the rotation axis direction. When a work is ground at heavy duty with the rotary grinding wheel 40, corner portions at both side sections 42 shown by two-dot chain lines are easily depleted in the initial state, and a roundness R is formed. When the roll of a rolling machine is ground with the rotary grinding wheel 40 formed with the roundness R, no feed pattern is left even if grinding is applied at heavy duty for a rough surface finish, and the satisfactory surface state is obtained.