An overvoltage protector having a housing and at least one overvoltage limiter arranged in the housing, especially a gas-filled surge arrester (1), a suppressor diode (2) or a varistor. The functional ability and the state of the overvoltage protector can be controlled during operation by associating a monitoring component with the overvoltage limiter which detects a current (i) flowing over the overvoltage limiter component, and by providing an evaluation unit that evaluates the signal of the monitoring component.