Abstract: A silicon substrate analyzing device with which impurities such as trace metals in a silicon substrate having a thick nitride film or oxide film formed on a silicon substrate surface can be analyzed with a high precision by ICP-MS. The silicon substrate analyzing device includes a load port, a substrate transportation robot, an aligner, a drying chamber, a gas-phase decomposition chamber, an analysis scan port having an analysis stage and a substrate analyzing nozzle, an analysis liquid collecting means, and an analysis means for performing inductively coupled plasma mass spectrometry. The silicon substrate having an oxide film or a nitride film formed on the silicon substrate is subjected to scanning the surface of the silicon substrate with a high-concentration recovered liquid with use of the substrate analyzing nozzle so that the high-concentration recovered liquid is recovered.