The present disclosure provides a rack bar supporting device of a steering apparatus for a vehicle. The rack bar supporting device includes: a support yoke to support a rack bar; a first cam member configured to have a front surface supporting the support yoke toward the rack bar and to have a rear surface provided with a first cam surface inclined in a circumferential direction thereof; a second cam member configured to have a front surface provided with a second cam surface inclined in a circumferential direction thereof to correspond to the first cam surface, to have a rear surface to which one end of a torsion spring is supported and coupled; a yoke plug; and an elastic pin.