An ion exchanger for a coolant circuit is provided with a housing that has an inlet and an outlet for a coolant. An ion exchanger medium is disposed in the housing. The housing is made of a plastic material and is an injection-molded part. A first plastic filter element is arranged in the outlet and embedded by injection molding in the first plastic material of the housing. In the inlet, a second plastic filter element is arranged and embedded by injection molding in the plastic material of the housing.