To shorten a waiting time for a belongings inspection, the present invention provides an inspection system 10 including: an electromagnetic wave transmission/reception unit 11 that irradiates an electromagnetic wave having a wavelength of equal to or more than 30 micrometers and equal to or less than one meter, and receives a reflection wave; a detection unit 12 that performs detection processing of detecting an abnormal state, based on a signal of the reflection wave; a decision unit 13 that decides, for an inspection target person from which the abnormal state is detected, whether to perform a secondary inspection at a place or perform a secondary inspection later; and a registration unit 16 that registers, in association with a result of the detection processing, identification information about the inspection target person decided that a secondary inspection is performed later.