To provide a downsized electrostatic sensor which increases performance.

The electrostatic sensor includes a sensor portion E1, including two capacitors constituted of movable electrodes 15, 15 and stationary electrodes 25, 25; an IC portion E2 disposed spatially separately from the sensor portion E1 and cooperating with the sensor portion E1; and first and second cover substrates 2 and 3 for sealing the sensor portion E1 and the IC portion E2 from both sides in the thickness direction. Each of the cover substrates 2, 3 is formed by using glass substrates 20, 30 that is a low dielectric substrate; the sensor portion E1 and the IC portion E2 are electrically connected by first through-wiring 21, formed on the first cover substrate 2 and electrically connected to the sensor portion E1, second through-wiring 22 formed on the first cover substrate 2 and electrically connected to the IC portion E2; and surface wiring 26, installed on a surface in the first cover substrate 2 located on a side opposite the sensor portion E1 and the IC portion E2 to connect the first through-wiring 21 and the second through-wiring 22.