A measuring method and apparatus in which a measurable object (23) is irradiated with acoustically induced electromagnetic waves to measure an electric property from one or more characteristics selected from the group which consists of intensity, phase, and frequency characteristics of said electromagnetic waves. The electric property of said measurable object (23) includes a change or changes in one or more of property values selected from the group which consists of electric field, dielectric constant, and spatial gradient of electric field or spatial gradient of dielectric constant of said measurable object and concentration, mass, size, shape, and number of charges of charged particles which said measurable object (23) possesses and interaction of said charged particles with a medium surrounding said charged particles.
