So far, gyromagnetic property of ferrite have played important role in microwave devices such as circulators, isolators but we have issues of incompatibility to integrated circuit and requirement of static magnetic bias field. The gyrotropic provides “non-reciprocity” for wave propagation and it is originated from unidirectional motion of spin. In my talk, creation of artificial gyromagnetism by combination of transistor and electromagnetic structure and its application will be presented.