A capacitive sensor, comprising a sensor sheet (2, 2') and a measuring instrument, the sensor sheet (2, 2') including: - a central electrode layer (12A, 101A - 116A); - a first dielectric layer (11A, 120) laminated on the upper surface of the central electrode layer (12A, 101A - 116A); - a second dielectric layer (11B, 130) laminated on the lower surface of the central electrode layer (12A, 101A - 116A); - a first outer electrode layer formed on the surface of the first dielectric layer (11A, 120) on the opposite side of the central electrode layer side; and - a second outer electrode layer formed on the surface of the second dielectric layer (11B, 130) on the opposite side of the central electrode layer side, - in which the first dielectric layer (11A, 120) and the second dielectric layer (11B, 130) are formed from elastomers, - -wherein the part where the central electrode layer (12A, 101A - 116A) and the first outer electrode layer face each other is designated as a first detection portion, while the part where the central electrode layer (12A, 101A - 116A) and the second outer electrode layer face each other is designated as a second detection portion, - wherein the sensor sheet (2, 2') is reversibly deformable, and the capacitances of the first detection portion and the second detection portion change with deformation, and - the measuring instrument being connected to the central electrode layer (12A, 101A - 116A), the first outer electrode layer and the second outer electrode layer and being configured to measure the capacitances of the first detection portion and the second detection portion, - wherein the measuring instrument is configured to measure the state of deformation of the sensor sheet (2, 2') on the basis of the total capacitance by adding the capacitance of the first detection portion and the capacitance of the second detection portion, - wherein the measuring instrument includes a circuit capable of measuring capacitance using alternating current impedance, - wherein the measuring instrument includes a CV conversion circuit, the central electrode layer (12A, 101A - 116A) is electrically connected to the CV conversion circuit side, and the first outer electrode layer and the second outer electrode layer are electrically connected to the alternating current signal generation side of the measuring instrument, - characterized in that the CV conversion circuit is a CV conversion circuit utilizing a half-wave voltage doubler rectifier circuit. - a central electrode layer (12A, 101A - 116A); - a first dielectric layer (11A, 120) laminated on the upper surface of the central electrode layer (12A, 101A - 116A); - a second dielectric layer (11B, 130) laminated on the lower surface of the central electrode layer (12A, 101A - 116A); - a first outer electrode layer formed on the surface of the first dielectric layer (11A, 120) on the opposite side of the central electrode layer side; and - a second outer electrode layer formed on the surface of the second dielectric layer (11B, 130) on the opposite side of the central electrode layer side, - in which the first dielectric layer (11A, 120) and the second dielectric layer (11B, 130) are formed from elastomers, - -wherein the part where the central electrode layer (12A, 101A - 116A) and the first outer electrode layer face each other is designated as a first detection portion, while the part where the central electrode layer (12A, 101A - 116A) and the second outer electrode layer face each other is designated as a second detection portion, - wherein the sensor sheet (2, 2') is reversibly deformable, and the capacitances of the first detection portion and the second detection portion change with deformation, and - the measuring instrument being connected to the central electrode layer (12A, 101A - 116A), the first outer electrode layer and the second outer electrode layer and being configured to measure the capacitances of the first detection portion and the second detection portion, - wherein the measuring instrument is configured to measure the state of deformation of the sensor sheet (2, 2') on the basis of the total capacitance by adding the capacitance of the first detection portion and the capacitance of the second detection portion, - wherein the measuring instrument includes a circuit capable of measuring capacitance using alternating current impedance, - wherein the measuring instrument includes a CV conversion circuit, the central electrode layer (12A, 101A - 116A) is electrically connected to the CV conversion circuit side, and the first outer electrode layer and the second outer electrode layer are electrically connected to the alternating current signal generation side of the measuring instrument, - characterized in that the CV conversion circuit is a CV conversion circuit utilizing a half-wave voltage doubler rectifier circuit.