A silicon substrate analyzing device comprising: a load port for placing thereon a storage cassette that stores a silicon substrate to be analyzed, wherein an oxide film and/or a nitride film has been formed on the silicon substrate; a substrate transportation robot capable of taking out, transporting, and installing the silicon substrate stored in the load port; an aligner for adjusting a position of the silicon substrate; a drying chamber for heating and drying the silicon substrate; a gas-phase decomposition chamber for etching the silicon substrate with an etching gas; an analysis scan port having an analysis stage for mounting thereon the silicon substrate, and a substrate analyzing nozzle for scanning a surface of the silicon substrate mounted on the analysis stage with an analysis liquid and collecting the analysis liquid into which the impurities such as trace metals have been transferred, wherein the analysis liquid is a mixture liquid of hydrogen fluoride and hydrogen peroxide; an analysis liquid collecting means having an analysis container for putting into the analysis liquid recovered by the substrate analyzing nozzle; a nebulizer sucking the analysis liquid, which has been put in the analysis container; and an analysis means for performing inductively coupled plasma mass spectrometry on the analysis liquid supplied from the nebulizer, characterized in that the substrate analyzing nozzle holding a high-concentration recovered liquid at a tip end of the nozzle is adapted to scan the silicon substrate surface, wherein the high-concentration recovered liquid is a mixture liquid of hydrogen fluoride of 10% to 30% volume concentration and hydrogen peroxide of 1% to 30% volume concentration; and the substrate analyzing nozzle is further adapted to subsequently discharge and return onto the silicon substrate surface the high-concentration recovered liquid. a load port for placing thereon a storage cassette that stores a silicon substrate to be analyzed, wherein an oxide film and/or a nitride film has been formed on the silicon substrate; a substrate transportation robot capable of taking out, transporting, and installing the silicon substrate stored in the load port; an aligner for adjusting a position of the silicon substrate; a drying chamber for heating and drying the silicon substrate; a gas-phase decomposition chamber for etching the silicon substrate with an etching gas; an analysis scan port having an analysis stage for mounting thereon the silicon substrate, and a substrate analyzing nozzle for scanning a surface of the silicon substrate mounted on the analysis stage with an analysis liquid and collecting the analysis liquid into which the impurities such as trace metals have been transferred, wherein the analysis liquid is a mixture liquid of hydrogen fluoride and hydrogen peroxide; an analysis liquid collecting means having an analysis container for putting into the analysis liquid recovered by the substrate analyzing nozzle; a nebulizer sucking the analysis liquid, which has been put in the analysis container; and an analysis means for performing inductively coupled plasma mass spectrometry on the analysis liquid supplied from the nebulizer, characterized in that the substrate analyzing nozzle holding a high-concentration recovered liquid at a tip end of the nozzle is adapted to scan the silicon substrate surface, wherein the high-concentration recovered liquid is a mixture liquid of hydrogen fluoride of 10% to 30% volume concentration and hydrogen peroxide of 1% to 30% volume concentration; and the substrate analyzing nozzle is further adapted to subsequently discharge and return onto the silicon substrate surface the high-concentration recovered liquid.