A progressive cavity pump having at least - a stator, - a rotor rotating in the stator, - a drive for the rotor, - a pump housing which is connected to the stator and has at least one inlet or outlet opening for the medium to be conveyed, - a connection housing, which is arranged between pump housing and drive, - a connecting shaft connected to the drive, which is arranged in the connection housing at least in some regions, and - a coupling rod arranged in the pump housing, which is connected to the connecting shaft via a drive-side joint and to the rotor via a rotor-side joint, the pump housing having a drive-side housing connecting piece, to which the connection housing is connected, and the pump housing having a stator-side housing connecting piece, to which the stator is connected, characterized in that the drive-side housing connecting piece is detachable in such a manner that the drive-side joint can be exposed for maintenance or disassembly, in that the drive-side housing connecting piece has a fixed, first connecting-piece section and a second, displaceable connecting-piece section, which is axially displaceable with respect to the first connecting-piece section, in that the coupling rod is supported against dropping and/or against displacement in the course of the disassembly of the drive-side housing connecting piece, wherein the coupling rod is supported by an end-side connecting-piece wall of the displaceable second connecting-piece section, which is provided with an aperture, or wherein a separating wall is arranged in the drive-side housing connecting piece, which separates a drive-side chamber from the interior of the pump housing, wherein the separating wall has an aperture, through which the coupling rod is guided, so that the coupling rod is supported in the aperture in the course of the disassembly of the drive-side housing connecting piece. - a stator, - a rotor rotating in the stator, - a drive for the rotor, - a pump housing which is connected to the stator and has at least one inlet or outlet opening for the medium to be conveyed, - a connection housing, which is arranged between pump housing and drive, - a connecting shaft connected to the drive, which is arranged in the connection housing at least in some regions, and - a coupling rod arranged in the pump housing, which is connected to the connecting shaft via a drive-side joint and to the rotor via a rotor-side joint, the pump housing having a drive-side housing connecting piece, to which the connection housing is connected, and the pump housing having a stator-side housing connecting piece, to which the stator is connected, characterized in that the drive-side housing connecting piece is detachable in such a manner that the drive-side joint can be exposed for maintenance or disassembly, in that the drive-side housing connecting piece has a fixed, first connecting-piece section and a second, displaceable connecting-piece section, which is axially displaceable with respect to the first connecting-piece section, in that the coupling rod is supported against dropping and/or against displacement in the course of the disassembly of the drive-side housing connecting piece, wherein the coupling rod is supported by an end-side connecting-piece wall of the displaceable second connecting-piece section, which is provided with an aperture, or wherein a separating wall is arranged in the drive-side housing connecting piece, which separates a drive-side chamber from the interior of the pump housing, wherein the separating wall has an aperture, through which the coupling rod is guided, so that the coupling rod is supported in the aperture in the course of the disassembly of the drive-side housing connecting piece. the pump housing having a drive-side housing connecting piece, to which the connection housing is connected, and the pump housing having a stator-side housing connecting piece, to which the stator is connected, characterized in that the drive-side housing connecting piece is detachable in such a manner that the drive-side joint can be exposed for maintenance or disassembly, in that the drive-side housing connecting piece has a fixed, first connecting-piece section and a second, displaceable connecting-piece section, which is axially displaceable with respect to the first connecting-piece section, in that the coupling rod is supported against dropping and/or against displacement in the course of the disassembly of the drive-side housing connecting piece, wherein the coupling rod is supported by an end-side connecting-piece wall of the displaceable second connecting-piece section, which is provided with an aperture, or wherein a separating wall is arranged in the drive-side housing connecting piece, which separates a drive-side chamber from the interior of the pump housing, wherein the separating wall has an aperture, through which the coupling rod is guided, so that the coupling rod is supported in the aperture in the course of the disassembly of the drive-side housing connecting piece.