The invention relates to a device for finishworking of a forming tool for an auto body sheet metal part in which, in a first working step for identifying a surface region of a tool surface to be remachined, a sheet metal part which has been coated with a marking paint can be formed in a pressing process by means of the tool and, using the color impression of the sheet metal part on the tool surface, the surface region which is to be remachined is acquired, and then in a second working step the surface region to be remachined can be remachined by a corresponding surface treatment. According to the invention, the device has a machining apparatus which electronically acquires the tool surface with the color impression and, depending on the intensity of the color impression, determines the location and/or dimension of the surface area to be remachined and remachines it accordingly.