The invention relates to a lens used for optical module, aims to provide a lens used for optical module which has the intrinsic transparency and formability of the thermoplastic transparent resin, and also has excellent thermal endurance capable of enduring the reflow soldering process. The lens used for optical module of the invention is characterized in that: the surface of the lens shaped body made of thermoplastic transparent resin has a solidifying layer formed by heat or light solidification coating agent; the solidifying layer has a thickness of 1-100 mum and TMA thermal deformation temperature of above 300 degrees centigrade; the solidifying layer thickness rate in the formula is in the range of 3-15% at the center portion of the lens used for optical module, wherein solidifying layer thickness rate(%) = (solidifying layer thickness / lens thickness) X 100%.