A sensor unit is provided and includes a first substrate, first and second electrodes, an input portion disposed so that a gap exists between the substrate and the input portion, a plurality of first structures disposed in the gap and extending at least partially between the first substrate and the input portion, and a second insulating structure disposed on a side of the first structures that is away from the input portion, or between adjacent first structures. The sensor unit is configured to detect a change in capacitance between the first and second electrodes upon a change in position of the input portion relative to the first substrate.