<p>Disclosed is an optical device wherein the optical performance is not deteriorated by reflowing. Specifically disclosed is an optical device obtained by curing and molding an optical material mainly composed of at least a curable resin and a curing agent. This optical device is characterized in that when a 3 mm-thick test piece obtained by curing and molding the optical material is subjected to a heat treatment at 260°C for 3 minutes, change in transmittance of the test piece to 400 nm light before and after the heat treatment is within 10%.</p>
