Abstract: The invention relates to a system for regulating the pressure in an enclosure (1) that is to contain processed gas for manufacturing semiconductor components or micro- or nano-technology devices, the enclosure being connected by pipework (2) to a pump unit (3) comprising a dry mechanical primary pump (4) and at least one secondary pump (5). According to the invention, the system further comprises a speed controller (6) controlling simultaneously the speeds of rotation of the dry mechanical primary pump (4) and of said at least one secondary pump (5).