A touch sensor unit includes a pressure-sensitive sensor and a support that supports the pressure-sensitive sensor. The support includes a portion that is folded and overlapped with another portion of the support. The pressure-sensitive sensor is at least partially enclosed by the folded portion of the support and supported by the support. The overlapping portions of the support include a part adjacent to the pressure-sensitive sensor where two surfaces of the support are opposed to each other. One of the two surfaces includes a groove, and the other one of the two surfaces includes a projection that projects toward the groove. The projection is fitted into the groove.