What are electromagnetic waves? 　 　 Electromagnetic waves are the waves characterised by variations of electric and magnetic fields. It is known as radio waves, heat rays, light rays, etc. depending on the frequency. Radio waves are the basis of telecommunications and broadcasting, and also used in medical treatments, cooking, etc. They can be characterised in terms of their frequency. Frequency is determined the number of identical cycles per second, measured in hertz (Hz). 　 　 　 Electromagnetic waves are the waves characterised by variations of electric and magnetic fields. It is known as radio waves, heat rays, light rays, etc. depending on the frequency. Radio waves are the basis of telecommunications and broadcasting, and also used in medical treatments, cooking, etc. Broadcasts: radio and TV Microwave-oven: The microwave is used to heat the water in ingredients. Mobile phones Wireless local area network has become popular recently. Electronic money, personal identification, etc. Hyperthermia 　 　 　 　 　 the radio wave transmit the energy in open air, a radio wave can be unwanted for others, or the waves can be superimposed each other. Thus, broadcasts and telecommunications are operated under national laws and international regulations. Not only telecommunications and broadcasts, however, electromagnetic waves are emitted by use of electricity, such as microwave ovens, semiconductor switch in a small electronic part, and son on. And the unwanted electromagnetic waves can affect telecommunications and broadcasts. Even worse, digital components' errors are likely caused by the noise. be used without any disturbance. The electromagnetic disturbance is determined as an electromagnetic phenomenon that may be superimposed on a wanted signal. Electromagnetic compatibility (EMC) is determined as the ability of a device, equipment, or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. Since radio waves exists on the earth, as same as air or water for instance, it must be used without any disturbance. The electromagnetic disturbance is determined as an electromagnetic phenomenon that may be superimposed on a wanted signal. Electromagnetic compatibility (EMC) is determined as the ability of a device, equipment, or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. Our activities cover development of new accurate measuring method, evaluation of test sites and equipment, analysis of electromagnetic disturbance, investigation of biological effect of electromagnetic wave, and national and international regulation matters.