Provided is a contactless internal measurement device including an electromagnetic wave irradiation unit that irradiates an electromagnetic wave to a measurement subject, and an electromagnetic wave receiver that detects the electromagnetic wave reflected by the measurement subject. The electromagnetic wave irradiation unit is disposed to reduce a polarization component of the electromagnetic wave detected by the electromagnetic wave receiver, the polarization component being the same as a polarization component of the electromagnetic wave irradiated by the electromagnetic wave irradiation unit.