A method of producing optical elements using a substrate having a recess, which is capable of easily removing a film in the recess, and optical elements formed. The optical element comprises a substrate 1, an optical waveguide structure layer 10 of resin disposed in a part of the region on the substrate 1, and a recess 21 formed in the region where the optical waveguide structure layer 10 is not disposed. The optical waveguide structure layer 10 includes an optical waveguide 4 and a clad layer. A coupler layer is disposed between the substrate 1 and the optical waveguide structure layer 10, and the film thickness distribution range of the coupler layer in the region below the optical waveguide 4 is such that the minimum film thickness is not more than 30 angstroms and the maximum film thickness is not less than 20 angstroms.