The invention provides a sealing device which can be reduced in manufacture cost and easy to maintain. The sealing device is provided with a rotating body which is driven for transporting a workpiece to be sealed a sealing head which is opposite to the outer periphery of the rotating body across the workpiece to be sealed and simultaneously used for providing the workpiece to be sealed with heat for sealing a sealing head driving device which enables the sealing head to perform driving path movements towards the forward direction and to perform returning path movements towards the backward direction opposite to the forward direction, with respective to the transporting direction of the workpiece to be sealed a head contraposition part which can clamp the workpiece to be sealed together with the sealing head and is arranged inside the rotating body in a state of capable of performing driving path movements towards the forward direction and performing returning path movements towards the backward direction, with respective to the transporting direction of the sheet-shaped workpiece and a head contraposition part driving device which is in linkage with the driving path movements and the returning path movements of the sealing head so as to enable the head contraposition part to perform the driving path movements and the returning path movements and to provide a track of the workpiece to be sealed, which is clamped between the head contraposition part and the sealing head, during the driving path movements. When the sealing head and the head contraposition part perform the driving path movements jointly, the workpiece to be sealed is sealed in the state that the workpiece to be sealed is clamped between the head contraposition part and the sealing head. After the returning path movements are performed by the head contraposition part and the sealing head, identical sealing actions are conducted repeatedly.【課題】製造コストを低減でき、かつメンテナンスが容易なシール装置を提供する。【解決手段】 被シールワークを搬送するように駆動される
