Patent ID: 8314935

Claim:
A target substance-detecting apparatus for detecting a target substance in an analyte, comprising: a detecting device having a substrate on which metal structures capable of causing a plasmon resonance are arranged, an illumination optical system having a mechanism for illuminating an incident light containing a polarization component polarized in a first direction onto the detecting device to cross the arranged metal structures in the detecting device, a light-receiving device for receiving light containing the polarization component polarized in the first direction and transmitted through or reflected by the detecting device, and an arithmetic unit for calculating on signals from the light-receiving device to analyze a characteristic of the analyte; the metal structures being arranged at first intervals in lines in the first direction and at second intervals in lines parallel in a second direction intersecting the first direction, the first intervals being not more than 1/10 of a plasmon resonance wavelength, and the second interval being not less than ¼ of the plasmon resonance wavelength and not more than the plasmon resonance wavelength.