Disclosed herein are a tunable capacitance control circuit and a tunable capacitance control method. The tunable capacitance control method is a tunable capacitance control method by a tunable capacitance control circuit including an MIM capacitor, a plurality of FET switches, and a control unit, wherein the control unit outputs control signals allowing only one of the plurality of (n) FET switches to be switched on and the remaining (n−1) FET switches to be switched off to the plurality of FET switches, thereby obtaining a desired tunable capacitance value.