An FTIR touch panel (100) includes a light guide plate (11) and a prism (14) joined to the light guide plate (11). The prism (14) includes a side surface (14a), which is a joining portion that is joined to the light guide plate (11), and a groove (141) in which a light source (12) is inserted. Light emitted from the light source (12) is incident on the prism (14) through a wall surface of the groove (141), and travels from the prism (14) to the light guide plate (11) through the side surface (14a). Plating (200) is formed on a surface of the prism (14) over a region excluding the side surface (14a) and the wall surface of the groove (141). Accordingly, a touch panel having a high position detection accuracy can be provided.