Abstract: A hydraulic press for deep drawing has mutually reciprocating clamping rings (6, 13) for idly clamping a sheet metal blank (5) with a predetermined force. The clamping rings (6, 13) are operated each by their cylinder (9, 14). The press has a tool (4) for forming the sheet blank (5), and a power unit (10, 11, 16) for generating a relative movement between, on the one hand, the clamping rings (6, 13) and, on the other hand, the tool (4). During the forming phase, the working volumes of the cylinders (9, 14) are interconnected to a common volume to which there is further connected a pressure maintenance device wit a pressure sensor (22), a regulator valve (23) and a pump (28). The piston areas of the cylinders (9, 14) are suitably equal.