A steering column apparatus working in combination with an airbag system, in which the steering column apparatus is assembled with a steering wheel (W) having an airbag (A) and is driven telescopically, the steering column apparatus comprising: a moveable unit assembled with the steering wheel (W) at a front end portion of the moveable unit to be driven back and forth; a guide unit mounted to a portion of the moveable unit to guide back and forth a movement of the moveable unit ; a drive unit fixed to the guide unit to drive the moveable unit ; characterized in that the steering column apparatus further comprises an actuator unit fixing the drive unit to the guide unit , and provided with an inflator configured to be triggered in cooperation with an operation signal of the airbag (A), wherein the inflator is configured to generate a propulsive force and to integrally drive the moveable unit and the drive unit in a forward direction of the moveable unit while releasing a fixed state of the drive unit and the guide unit when the inflator generates the propulsive force, wherein the guide unit includes: a guide rod inserted through a rear end portion of the moveable unit to guide back and forth movement of the moveable unit ; and a guide cover covering the guide rod with being spaced from an external circumferential surface of the guide rod by a gap, and guiding the back and forth movement of the moveable unit , wherein the guide cover includes: a first guide slot in which a portion of the drive unit is engaged for guiding movement of the drive unit ; and a second guide slot in which a portion of the actuator unit is engaged for guiding movement of the actuator unit . a moveable unit assembled with the steering wheel (W) at a front end portion of the moveable unit to be driven back and forth; a guide unit mounted to a portion of the moveable unit to guide back and forth a movement of the moveable unit ; a drive unit fixed to the guide unit to drive the moveable unit ; characterized in that the steering column apparatus further comprises an actuator unit fixing the drive unit to the guide unit , and provided with an inflator configured to be triggered in cooperation with an operation signal of the airbag (A), wherein the inflator is configured to generate a propulsive force and to integrally drive the moveable unit and the drive unit in a forward direction of the moveable unit while releasing a fixed state of the drive unit and the guide unit when the inflator generates the propulsive force, wherein the guide unit includes: a guide rod inserted through a rear end portion of the moveable unit to guide back and forth movement of the moveable unit ; and a guide cover covering the guide rod with being spaced from an external circumferential surface of the guide rod by a gap, and guiding the back and forth movement of the moveable unit , a guide rod inserted through a rear end portion of the moveable unit to guide back and forth movement of the moveable unit ; and a guide cover covering the guide rod with being spaced from an external circumferential surface of the guide rod by a gap, and guiding the back and forth movement of the moveable unit , wherein the guide cover includes: a first guide slot in which a portion of the drive unit is engaged for guiding movement of the drive unit ; and a second guide slot in which a portion of the actuator unit is engaged for guiding movement of the actuator unit . a first guide slot in which a portion of the drive unit is engaged for guiding movement of the drive unit ; and a second guide slot in which a portion of the actuator unit is engaged for guiding movement of the actuator unit . <EOS>