There is provided an information processing device including a capacitance variation detection unit configured to detect an operation input to each of a plurality of key regions as a capacitance variation amount of a capacitive element, the key region being provided on a sheet-like operation member, the capacitive element being provided in association with each of the key regions, the capacitance variation amount being dependent on a change in a distance between the key region and the capacitive element, and an input state determination unit configured to determine whether an input state of the key region is an ON state based on the detected capacitance variation amount, the ON state being a state in which the operation input to the key region is decided to be valid. The input state determination unit determines an end of the ON state based on a differential value of the capacitance variation amount.