A conventional system for testing a semiconductor integrated circuit has a problem in that the time required to test it is long, the cost required for its test increases, and yields are reduced due to the occurrence of a failure in a test circuit itself. The system has a document indexer that accepts structured, semi-structured, or unstructured documents and creates an easily searchable index of the documents. Between the metal plate and the individual end faces of the yoke and the permanent magnet, there is interposed a high impedance member that prevents radio wave noise from flowing from the metal plate to the yoke and the permanent magnet. Accordingly, with use of the compound, the phosphorylated peptide can be easily identified.