A sealing apparatus capable of linear and rotational motion comprising: a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the first shaft or an outer circumferential surface of the second shaft, wherein the first shaft is provided to be capable of linear motion in an axial direction with respect to the housing, and the second shaft is provided to be capable of rotational motion and linear motion with respect to the first shaft, and wherein the third sealing member does not perform sealing between the first shaft and the second shaft when the second shaft is in a first position in the first shaft, and performs sealing between the first shaft and the second shaft when the second shaft moves to and is in a second position in the first shaft, characterized by the fact that the third sealing member is provided on the inner circumferential surface of the first shaft, and a groove portion is provided in the second shaft to form a predetermined gap with the inner circumferential surface of the third sealing member, wherein a ring-shaped coupling ring provided separately on the second shaft is mounted on the groove portion, such that in the first position, the third sealing member does not seal between the first shaft and the second shaft, and in the second position, the third sealing member seals between the first shaft and the second shaft by contacting the coupling ring on the second shaft. a housing; a hollow first shaft penetrating and coupled to the housing; a first sealing member provided between the housing and the first shaft to seal therebetween; a second shaft of which at least a part is inserted into the first shaft; a second sealing member provided between the first shaft and the second shaft to seal therebetween; and a third sealing member provided on either an inner circumferential surface of the first shaft or an outer circumferential surface of the second shaft, wherein the first shaft is provided to be capable of linear motion in an axial direction with respect to the housing, and the second shaft is provided to be capable of rotational motion and linear motion with respect to the first shaft, and wherein the third sealing member does not perform sealing between the first shaft and the second shaft when the second shaft is in a first position in the first shaft, and performs sealing between the first shaft and the second shaft when the second shaft moves to and is in a second position in the first shaft, characterized by the fact that the third sealing member is provided on the inner circumferential surface of the first shaft, and a groove portion is provided in the second shaft to form a predetermined gap with the inner circumferential surface of the third sealing member, wherein a ring-shaped coupling ring provided separately on the second shaft is mounted on the groove portion, such that in the first position, the third sealing member does not seal between the first shaft and the second shaft, and in the second position, the third sealing member seals between the first shaft and the second shaft by contacting the coupling ring on the second shaft.