A steering column apparatus working in combination with an airbag system, in which the steering column apparatus is assembled with a steering wheel having an airbag and is driven telescopically, the steering column apparatus comprising: a moveable unit assembled with the steering wheel 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, 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 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, 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.