Analysis method and analysis device

An analysis method comprising:

• irradiating, with laser light, an analysis substrate made of a resin material and having a reaction region on which detection target substances and nanoparticles of a metal compound for labeling the detection target substances are captured;
• extracting, as a substrate signal level, a signal level generated when receiving reflected light from a non-reaction region in the analysis substrate at which the reaction region is not formed;
• receiving reflected light from the reaction region to generate a light reception level signal;
• extracting a nanoparticle detection signal having a higher signal level than the substrate signal level from the light reception level signal of the reflected light from the reaction region;
• and
• detecting the nanoparticles in accordance with the extracted nanoparticle detection signal,
• wherein the nanoparticles have a complex refractive index n−ki, where an extinction coefficient k of an imaginary part ki is 0.3 or smaller and a refractive index n of a real part is in a range of 2.1 to 2.5, or where an extinction coefficient k of an imaginary part ki is 0.2 or smaller and a refractive index n of a real part is in a range of 2.1 to 2.6.