An RF MEMS switch having asymmetrical spring rigidity. The RF MEMS switch has supporting members spaced apart in a certain interval on a substrate, a membrane being a motion member suspended by plural spring members extended on both sides of the membrane, and a bottom electrode being a contact surface on an upper surface of the substrate facing a bottom surface of the membrane, wherein the plural spring members placed on opposite sides of the membrane have asymmetrical rigidity, and a portion of the membrane on a side of stronger spring rigidity is first separated from the contact surface when the RF MEMS switch is turned off. The present invention has an advantage of easy separation of the switch from the contact surface, when the switch is turned off, due to the different rigidity of the springs located on the sides of the membrane.