The waterproof case includes a case body, which defines an inner space for accommodating an electrically functional component. The waterproof case includes at least one opening, and at least one plug, which is mounted in the opening to form a part of a wall of the inner space. The plug includes at least one terminal conduit forming a feedthrough for a terminal. The plug is arranged in the opening to form with the case body an external space, and the external space is filled with an electrically insulating material for sealing the waterproof case.