A device for processing welding electrodes with a grinding surface driven by a driving motor with a shaft, which faces the motor and runs in a housing, wherein at least one opening is provided in the housing for guiding a welding electrode for grinding in a defined position relative to the grinding wheel. The housing is releasably fixed to a motor flange for bearing the shaft, and the grinding wheel is arranged on a side of the motor flange which is remote from the motor. The motor flange is formed by a sleeve, which is adapted to be stuck onto the housing in such a way, that at least one opening extends from the circumference of the housing towards the grinding surface facing the motor.