An electrostatic capacity sensor 1 capable of expanding a force detectable region includes an upper electrode 11, a lower electrode 11 for detecting electrostatic capacity C between the lower electrode 11 and the upper electrode 11, and a base material 12 having dielectric properties and elasticity and disposed between upper and lower electrodes 11 and 11. An upper base material layer portion 12a and a lower base material layer portion 12b of the base material 12 are configured such that elastic deformation amounts when the same force is applied are different from each other.