Disclosed is a capacitive RF-MEMS switch. The switch comprises an insulating plate, first to third microstrip lines, an insulating dielectric, N anchor points, and a switch piece. The switch piece comprises a movable metal film and N elastic fixed beams. The first to third microstrip lines are sequentially disposed on the insulating plate. The insulating dielectric is placed on the second microstrip line. The N anchor points are disposed on a microstrip line different from the second microstrip line. One end of the N elastic fixed beams of the switch piece is respectively connected to the movable metal film, and the other end of the switch piece is connected to the anchor points. The elastic fixed beams in the present invention have low elastic coefficients so that a pull-down voltage of the switch is decreased, thereby obtaining a high switching capacitance ratio and a high radio frequency turn-off property. Accordingly, the speed of the switch is fast. At the same time, decreasing the elastic coefficient of the switch can decrease a driving voltage thereof. On the other hand, a novel elastic fixed beam structure is used for the switch, which can reduce the switch area compared with the conventional long fixed beam.
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