A hydrodynamic retarder, comprising 1.1 a bladed rotor and a bladed stator, which form together a working chamber which can be filled with working medium and emptied thereof; 1.2 at least one first working medium connection for feeding working medium into the working chamber; and a second working medium connection for discharging working medium from the working chamber; 1.3 a working medium container, which limits a working medium storage volume for accommodating working medium which is not situated in the working chamber at that time, wherein the working medium container comprises an outlet, which is connected via at least one line to the first working medium connection for conveying the working medium, and moreover one inlet, which is connected via at least one line to the second working medium connection for conveying the working medium; and 1.4 the working medium container consists of at least two housing parts (8, 9), which are assembled along at least one parting line; wherein 1.5 both housing parts (8, 9) enclose together the working medium storage volume; 1.6 at least one of both housing parts forms simultaneously a portion of a retarder housing, which carries or forms the stator and forms all the connections for conveying the working fluid, or a portion of the latter, between the working medium storage volume and the working chamber at least partially; characterised in that 1.7 a separating plate is inserted between both housing parts (8, 9), which plate forms together with one or both housing parts (8, 9) cavities for the working medium-conducting connections and/or the working medium storage volume. 1.1 a bladed rotor and a bladed stator, which form together a working chamber which can be filled with working medium and emptied thereof; 1.2 at least one first working medium connection for feeding working medium into the working chamber; and a second working medium connection for discharging working medium from the working chamber; 1.3 a working medium container, which limits a working medium storage volume for accommodating working medium which is not situated in the working chamber at that time, wherein the working medium container comprises an outlet, which is connected via at least one line to the first working medium connection for conveying the working medium, and moreover one inlet, which is connected via at least one line to the second working medium connection for conveying the working medium; and 1.4 the working medium container consists of at least two housing parts (8, 9), which are assembled along at least one parting line; wherein 1.5 both housing parts (8, 9) enclose together the working medium storage volume; 1.6 at least one of both housing parts forms simultaneously a portion of a retarder housing, which carries or forms the stator and forms all the connections for conveying the working fluid, or a portion of the latter, between the working medium storage volume and the working chamber at least partially; characterised in that 1.7 a separating plate is inserted between both housing parts (8, 9), which plate forms together with one or both housing parts (8, 9) cavities for the working medium-conducting connections and/or the working medium storage volume.