Disclosed is a center hole machining method such that even if the machining allowance for a shaft blank is set to be small, the surface of the blank will not remain after machining. This center hole machining method is provided with first to fifth steps. The first step obtains outer peripheral shape data at a plurality of axial locations of the shaft blank. The second step compares each of the pieces of measured data at the plurality of locations with the corresponding piece of design data, thereby finding a center axis line for establishing center holes. The third step calculates the minimum distances from the center axis line to the shaft blank outer periphery at the plurality of locations. The fourth step is such that if the minimum distances at all the locations are larger than machining dimensions, then the center axis line is determined to be correct, and that if any of the minimum distances fails to exceed a machining dimension, then the center axis line is moved in a direction in which said any of the minimum distances becomes larger than the machining dimension, and the third step is executed over again on the basis of the center axis line thus moved. The fifth step forms center holes at those points on the end faces of the shaft blank which are located on the extension of the center axis line that is determined to be correct.