In a case where a railway vehicle is measured using a coordinate measuring machine 20 in which an operator manually specifies measurement spots, much time is required to specify measurement spots, erroneous measurement may be performed, and much time is required to extract a dimension based on measurement coordinates. The present invention includes a probe having a stylus 105 with a ball 104 that comes into contact with a measurement spot attached at a tip, a three-dimensional measuring machine measuring a coordinate of the ball 104 of the probe, and a processing unit including a data table, wherein the processing unit stores a data related to a reference point provided on the railway vehicle in the data table, and performs mapping of a three-dimensional measured coordinate and a three-dimensional reference coordinate of each measurement, and performs dimension calculation of the railway vehicle, based on a coordinate error between the three-dimensional reference coordinate of the reference point and the thre
