A shaft coupling mechanism for an electric power steering apparatus includes a coupling base body coupled to a rotating shaft on a side of an electric motor; a coupling base body coupled to a steering shaft; rotation transmitting members interposed between both coupling base bodies and adapted to transmit the rotation of the rotating shaft in an R direction to the steering shaft through both coupling base bodies; an intermediate interposed member interposed between the coupling base bodies; and a coupling means for coupling the rotation transmitting members to each other.