To provide a compound lens having configuration with which a plurality of lenses can be fitted to each other and can be positioned at prescribed relative positions without causing load worsening assembly accuracy in an optical axis direction and a direction orthogonal to the optical axis direction and to provide a molding die with which molding processing of the compound lens can be suitably performed.

The compound lens is constituted so that the first lens 2 and the second lens 3 are mutually assembled in an optical axis direction while regulating relative positions in an orthogonal direction by fitting a fitting inner peripheral surface 25 having a cross sectional shape of a line being parallel to the optical axis of a lens surface 22 in a first lens 2 and a fitting outer peripheral surface 33 having the cross sectional shape of a line being parallel to the optical axis of a lens surface 31 in a second lens 3 to each other with a clearance with which deviation amount of respective optical axes of the first lens 2 and the second lens 3 is within a range where desired optical performance can be obtained.