Patent ID: 7893400

Claim:
A substrate for supporting a sample to be subjected to a spectrum analysis in a laser desorption/ionization mass spectrometer performing laser desorption/ionization mass spectrometry based on ions generated by exposing the sample supported on the substrate to laser light, the substrate comprising: a material from which ions thereof are easily generable in response to the exposure to the laser light, the material being provided at least a surface of the substrate, so that the ions generated from the material are determined to be index ions and a signal to become noise in the laser desorption/ionization mass spectrometry is determined using a signal of the index ions, thereby performing the spectrum analysis without an effect of the noise, wherein when the substrate is exposed to the laser light with varying intensity with a solution containing a plurality of different salts as solutes being applied evenly on the substrate, the ions of the material are observed whenever univalent positive ions of the solution are observed.