A coating device for coating components, in particular for nickel-plating spark plug housings. The coating device includes: a housing having an outer anode that is designed to receive the component, an inner anode that can be introduced into a through-opening of the component, and a voltage-generating device, the voltage-generating device being designed to generate a first voltage between the outer anode and the component, as well as a second voltage between the inner anode and the component. The housing has an inlet and an outlet for introducing and discharging a process medium into or out of the housing.