An imaging lens unit configured for processing by a solder reflow process, and includes a lens group of one or more lenses; and a lens tube supporting the lens group. The imaging lens unit comprises one or more cationically-cured epoxy resin lenses formed from an cationically-curable epoxy resin material, the lens tube is formed from a thermoplastic resin material having a deflection temperature under load of at least 200° C. The imaging lens unit has a clearance between the lens tube and at least one of the cationically-cured epoxy resin lenses and has lens supporting portions provided at least three locations inside the lens tube that support the at least one cationically-cured epoxy resin lens. The lens unit can be miniaturized. The imaging lens unit also provides excellent optical characteristics without deteriorating the optical characteristics in alignment of the centers of the lens and the diaphragm.