A device for clamping a workpiece (P) to a workbench (T) includes a body (1) containing a vacuum-generating element. The body (1) has a lower cavity (2) open at the bottom and positioned in the vicinity of a face for securing to the workbench (T). The lower cavity (2) forms a vacuum reserve, this vacuum reserve being connected by a substantially straight duct (6) to an upper face for securing a workpiece (P).