To obtain an apparatus and a method in which a stuck organic substance can be identified and quantitatively determined with high accuracy by heating a region to be analyzed on the surface of a sample from its rear and collecting its desorbed gas to be analyzed.

A region to be analyzed and evaluated (a region to be analyzed) 2a on the surface of a wafer 2 is heated locally from its rear by a heating heater 3. A desorbed gas from the surface of the wafer 2 is analyzed, and an organic substance is analyzed locally. The desorbed gas from the wafer 2 is superposed on a carrier gas so to be passed through a collecting tube 5, it is collected by a desorbed-gas collection means 6, the organic substance in the desorbed gas is analyzed by a desorbed-gas analysis means 7, and it is identified and quantitatively determined. As the desorbed-gas analysis means 7, a GC/MS method is effective, but other method may be used. Thereby, the organic substance on the surface of the wafer 2 can be analyzed locally, and the distribution of the organic substance stuck to the surface of the wafer 2 can be evaluated.