In effecting two-sided surface grinding for surface-grinding the opposite surfaces of a workpiece simultaneously by a pair of oppositely disposed grinding wheels, infeed grinding is performed by oscillating the workpiece within the range where the surfaces to be ground of the workpiece do not protrude from the inner and outer peripheries of the grinding wheel surfaces of the grinding wheels, and then through-grinding is performed by feeding the workpiece to allow the surfaces to be ground to pass along the inner and outer peripheries of the grinding wheel surfaces. As an effect, worn wheel edges or the like can be prevented from being formed in the inner and outer peripheral edges, that grinding wheel surfaces can be maintained in proper shape for a prolonged time, that the grinding accuracy is better, and that dress interval can be prolonged, thus improving the life of grinding wheels.