A support for a tablet computer includes a base shaped to stably rest both on flat and on curved surfaces, a mechanical system for removably fixing the base securely to a key processing machine to be connected to and controlled by the tablet, a tubular element fixed on the upper surface of the base, a cylindrical member housed in the interior of the tubular element and rotatable relative thereto, first members for resting on and coupling to the lower transverse edge of the tablet and second members for resting on and coupling to the upper transverse edge of the tablet, wherein the first members and the second members are disposed at an angle to each other and are associated with the cylindrical member to rotate therewith relative to the tubular element, the relative distance between said the resting and coupling members and the second resting and coupling members being adjustable.