The present invention relates to a hydrodynamic machine, especially a hydrodynamic retarder, including a bladed primary wheel and a bladed secondary wheel which are arranged opposite of each other axially with respect to their blade configurations such that they jointly form a working chamber. The working chamber can be filled with a working medium for one operating state in order to transmit torque from the primary wheel to the secondary wheel by means of a circulatory flow of the working medium. The working chamber can be emptied of the working medium for a non-operating state in order to prevent a transmission of torque from the primary wheel to the secondary wheel. A suction apparatus is connected with a fluidic connection to the working chamber in order to suck off working medium and/or air from the working chamber for forming a negative pressure in the working chamber in the non-operating state.