The efficiency of the work for measuring electromagnetic waves is increased. A measuring device includes a position information obtaining unit, an electromagnetic wave information obtaining unit, a data storage unit, and a selecting unit. The position information obtaining unit obtains position information of a reflective prism 202, which is measured by a position measuring device 400. The electromagnetic wave information obtaining unit obtains illuminance information measured by an illuminometer 203, which is in the proximity of the reflective prism 202. The data storage unit stores the position information of the reflective prism 202 and the illuminance information in association with each other. The selecting unit compares information of predetermined measurement planned positions with the position information of the reflective prism 202 and selects the illuminance information at a position that has a specific relationship relative to one of the measurement planned positions.