Abstract: Provided is a clamping device such that improvement can be made in the degree of freedom of machining and the degree of freedom in dealing with the shape of the workpiece. This clamping device (1) serves to secure the workpiece, and is provided with a first grip section (12) which is disposed on an inner surface of a frame body (11) and has a plurality of protrusions (123) that project inward; a second grip section (13) which is disposed on a different inner surface of the frame body (11) and has a plurality of protrusions (133) that project inward, said different inner surface facing the inner surface whereon the first grip section (12) is disposed; and a grip section driving section (14) which moves the first grip section (12) and the second grip section (13) in a direction approaching each other or in a direction moving away from each other.