An assembling jig for assembling an optical connector is provided. The optical connector has a pair of beam portions having elasticity and adapted to hold a ferrule holding an optical fiber. The assembling jig includes a body portion, an optical connector receiving portion movably held by the body portion and adapted to receive the optical connector, a ferrule receiving portion movably held by the body portion and adapted to receive the ferrule, and an abutting portion adapted to abut the pair of beam portions to open the pair of beam portions outward.