The invention relates to a process for producing a thin layer (22) of porous DLC, to the use of a PECVD plant (2) and to a workpiece (16) having a surface (20) coated with a porous DLC layer (22). In a process for producing a thin DLC layer (22), a carbon-containing precursor gas is introduced into a recipient (4) for depositing a DLC layer on the surface (20) to be coated of a workpiece (16), wherein the DLC layer (22) is deposited at a working pressure of between 20 * 10-3 and 30 * 10-3 mbar and a BIAS voltage of between -250 V and -150 V. Subsequently, a gas for etching back is introduced into the recipient (4) and DLC existing on the surface (20) of the workpiece (16) is etched back at a working pressure of between 200 * 10-3 and 300 * 10-3 mbar and a BIAS voltage of between -430 V and -330 V. This process is repeated multiple times.
