A position sensor includes: a sheet-form optical waveguide including a sheet-form under cladding layer, a plurality of linear cores arranged in a lattice form and formed on a surface of the under cladding layer, and a sheet-form over cladding layer covering the cores; a light-emitting element connected to one end surface of the cores; and a light-receiving element connected to the other end surface of the cores. The cores have an elasticity modulus higher than that of the under cladding layer and that of the over cladding layer. The deformation rate of a cross section of the cores as seen in a pressed direction is lower than the deformation rates of cross sections of the over cladding layer and the under cladding layer when a surface of the sheet-form optical waveguide is pressed.