A suction cup unit for gripping workpieces, wherein said suction cup unit comprises a suction cup member carried by a support body , and wherein the support body of the suction cup member also carries a vacuum generating device configured to autonomously generate a vacuum to be applied to the suction cup member , wherein said vacuum generating device includes: - an ejector-effect device , comprising a nozzle configured to generate a vacuum at a nozzle auxiliary outlet when a flow of pressurized air is fed through said nozzle , - at least one electrically-operated valve in the flow of pressurized air to the nozzle , and - a line for connecting said nozzle to said suction cup member , in order to transmit a vacuum to said suction cup member when pressurized air is fed through said nozzle , said suction cup unit being characterized in that : - said support body carrying the suction cup member and the vacuum generating device is in the form of a container, - said suction cup unit includes a reservoir within said container, the reservoir being charged with pressurized air, - said electrically-operated valve is interposed in the connection between the reservoir of pressurized air and the nozzle , for controlling communication between the reservoir and the nozzle , so that an independent vacuum source is provided inside said suction cup unit, without resorting to a suction pump. wherein said vacuum generating device includes: - an ejector-effect device , comprising a nozzle configured to generate a vacuum at a nozzle auxiliary outlet when a flow of pressurized air is fed through said nozzle , - at least one electrically-operated valve in the flow of pressurized air to the nozzle , and - a line for connecting said nozzle to said suction cup member , in order to transmit a vacuum to said suction cup member when pressurized air is fed through said nozzle , - an ejector-effect device , comprising a nozzle configured to generate a vacuum at a nozzle auxiliary outlet when a flow of pressurized air is fed through said nozzle , - at least one electrically-operated valve in the flow of pressurized air to the nozzle , and - a line for connecting said nozzle to said suction cup member , in order to transmit a vacuum to said suction cup member when pressurized air is fed through said nozzle , said suction cup unit being characterized in that : - said support body carrying the suction cup member and the vacuum generating device is in the form of a container, - said suction cup unit includes a reservoir within said container, the reservoir being charged with pressurized air, - said electrically-operated valve is interposed in the connection between the reservoir of pressurized air and the nozzle , for controlling communication between the reservoir and the nozzle , - said support body carrying the suction cup member and the vacuum generating device is in the form of a container, - said suction cup unit includes a reservoir within said container, the reservoir being charged with pressurized air, - said electrically-operated valve is interposed in the connection between the reservoir of pressurized air and the nozzle , for controlling communication between the reservoir and the nozzle , so that an independent vacuum source is provided inside said suction cup unit, without resorting to a suction pump. <EOS>