To provide a polymerizable monomer capable of giving a cured product with high refractive index and large Abbe number and high light resistance, and excellent in preservation stability in itself.

This polymerizable monomer is a dithiane ring-containing thio(meth)acrylate compound having in the molecule a dithiane ring, thioether linkages and thioester linkages, for example, having two polymerizable unsaturated bonds as shown by the structural formula.