Disclosed herein is a massage device having a shape-changeable structure. According to an embodiment of the present disclosure, there is disclosed a massage device including a seat frame configured to support buttocks of a user, a link frame of which one end is connected to one end of the seat frame, and a link sub-frame connected to the other end of the link frame and disposed between the link frame and a driving force providing part, wherein an angle between the link frame and the seat frame is maintained at a predetermined angle, and an angle between the link frame and the link sub-frame changes according to the movement of the driving force providing part.