Method for operating a plasma process and arc discharge detection device

12An arc discharge in a plasma process is detected using a method that includes detecting arc discharges by monitoring one or more characteristic values of the plasma process, and comparing at least a first characteristic value with a predefinable first threshold value (SW). When it is determined that the at least first characteristic value reaches the first threshold value, a potential arc discharge is recognized and a first countermeasure is triggered to suppress the arc discharge. The method includes comparing at least a second characteristic value with a pre-definable second threshold value (SW) that differs from the first threshold value, and when it is determined that the second characteristic value reaches the second threshold value, triggering a second countermeasure for suppressing the arc discharge. After the second countermeasure has been triggered, a renewed triggering of the second countermeasure is prevented during a blocking time (Tt).