A rolling bearing for a balancer shaft device has a cylindrical section which is, in a radial cross-section, on an imaginary circle coaxial with the axis of the shaft section of the balancer shaft and which covers the shaft section. The outer peripheral surface of the cylindrical section is configured as the inner ring raceway surface of the inner ring member on which the rolling bodies of the rolling bearing roll. At a position of the shaft section of the balancer shaft, the position being that at which the rolling bearing is disposed, the portions of the shaft section which do not contribute to cancel rotational vibration are configured as unfilled portions.
