PURPOSE: To improve the economy by short verification and reduction in size of a detecting system with high sensitivity by measuring the change of dielectric properties of a test mixture in a microwave region.

CONSTITUTION: Liquid-like test mixture containing fine particles covered with ligand, its coupling analog edge or bond partner and test specimen is formed. When the particles are covered with the ligand or its coupling analog edge, the mixture is formed to further include bond partner of ligand diffusion type (the covered particles have significantly different effective relative permittivity from the relative permittivity of the mixture in the state that no ligand is in the specimen). The change of the relative permittivity of the mixture in the microwave region as the quantity of the ligand in the mixture or the function of the presence is measured.