A touch panel includes a light-transmissible, piezoelectric substrate having a first surface and a second surface opposite to the first surface of the piezoelectric substrate, a first light transmissible, resistor layer provided on the first surface of the substrate, and a second light transmissible, resistor layer provided on the second surface of the substrate. Each of the positioning holes has an inserting portion and a positioning portion, and each of the positioning columns has a head portion capable of passing through the inserting portion of the corresponding positioning hole and a neck portion connected to the head portion and capable of engaging with the positioning portion of the corresponding positioning hole. The cams may include contact surfaces that are inclined relative to each other in an axial direction of the cams, and when a contact surface of one of the cams slides along a contact surface of the other cam, a distance between the pair of cams may be changed to deform the elastic member.