The invention relates to an electric coolant pump comprising a pump housing, a rotating conveying element for accelerating the coolant, a pump shaft passing through the pump housing and on which the conveying element is mounted, an electric motor for driving the pump shaft; and a control circuit. The conveying element is arranged in a pump chamber formed by the pump housing and a spiral lid. The electric motor is arranged in a motor chamber formed by the pump housing and motor lid. Furthermore, a control circuit chamber is formed in the pump housing, for the control circuit. The control circuit chamber has an opening through which the control circuit can be inserted into the control circuit chamber.