There is provided an input device including an optical waveguide that prevents cores from being cracked due to pressing with and movement of a tip input part of an input element. This input device includes an optical waveguide in a rectangular sheet form configured such that linear cores arranged in a lattice form are held between an under cladding layer and an over cladding layer both in a rectangular sheet form. A surface region of the over cladding layer corresponding to part of the cores arranged in the lattice form serves as an input region. Gaps between adjacent ones of the linear cores arranged in the lattice form are in the range of 10 to 300 μm which is smaller than conventional gaps. The cores have an elasticity modulus equal to or higher than those of the under cladding layer and the over cladding layer.