Balance checking device, balance checking method, balance-checked crankshaft, arithmetic processing device, and program

The invention relates to a balance checking device, a balance checking method, a crankshaft after balance checking, an arithmetic processing device, and a program. An arithmetic processing unit (32) of a balance inspection device (100) generates three-dimensional point group data on the basis of a measurement result of a surface shape measurement unit (1), and generates surface data on the basis of the three-dimensional point group data aligned with a surface shape model specified in a coordinate system that becomes an X-axis by a rotational center axis (L) in the design of a crankshaft (S). Evaluation target data, which is surface data of an evaluation target portion including an arm (SC) of a crankshaft (S), is extracted, the center of gravity and the area of a cross-section orthogonal to the X-axis at a plurality of positions along the X-axis of the evaluation target data are calculated, and the evaluation target data is calculated on the basis of the center of gravity of the cross-section and a predetermi