Micropump for conveying a fluid from a low pressure inlet to a high pressure outlet, the pump having - an internal rotor with external teeth; - an outer rotor with internal teeth, and - a bearing element; wherein the external toothing of the inner rotor meshes with the internal toothing of the outer rotor and the inner rotor is arranged in a rotationally fixed manner on a shaft supported by the bearing element; - wherein the outer rotor is mounted eccentrically to the inner rotor in a rotor receptacle in a radial direction in order to cyclically open and close conveying chambers between the inner rotor and the outer rotor; - wherein the bearing element - has a fluid passage (24, 25, 26, 27, 28) for conveyed fluid leading from the conveying chambers to the high pressure outlet; - radially supports (4, 5) the shaft and forms an axial bearing for the inner rotor and the outer rotor (3, 13), the bearing element having a first radial bearing remote from the rotor and a second radial bearing close to the rotor, - wherein the shaft is supported in the radial direction exclusively by the bearing element with the two radial bearings (4, 5); - characterized in that - the shaft has a first diameter in the region of the radial bearing near the rotor, but has a wider or larger diameter than the first diameter in the region of the radial bearing far from the rotor; - and in that the fluid passage in the bearing element is fluidically connected to the radial bearings (4, 5) and the shaft projects through a portion of the fluid passage. - an internal rotor with external teeth; - an outer rotor with internal teeth, and - a bearing element; wherein the external toothing of the inner rotor meshes with the internal toothing of the outer rotor and the inner rotor is arranged in a rotationally fixed manner on a shaft supported by the bearing element; - wherein the outer rotor is mounted eccentrically to the inner rotor in a rotor receptacle in a radial direction in order to cyclically open and close conveying chambers between the inner rotor and the outer rotor; - wherein the bearing element - has a fluid passage (24, 25, 26, 27, 28) for conveyed fluid leading from the conveying chambers to the high pressure outlet; - radially supports (4, 5) the shaft and forms an axial bearing for the inner rotor and the outer rotor (3, 13), the bearing element having a first radial bearing remote from the rotor and a second radial bearing close to the rotor, - wherein the shaft is supported in the radial direction exclusively by the bearing element with the two radial bearings (4, 5); - characterized in that - the shaft has a first diameter in the region of the radial bearing near the rotor, but has a wider or larger diameter than the first diameter in the region of the radial bearing far from the rotor; - and in that the fluid passage in the bearing element is fluidically connected to the radial bearings (4, 5) and the shaft projects through a portion of the fluid passage. - has a fluid passage (24, 25, 26, 27, 28) for conveyed fluid leading from the conveying chambers to the high pressure outlet; - radially supports (4, 5) the shaft and forms an axial bearing for the inner rotor and the outer rotor (3, 13), the bearing element having a first radial bearing remote from the rotor and a second radial bearing close to the rotor, - wherein the shaft is supported in the radial direction exclusively by the bearing element with the two radial bearings (4, 5); - characterized in that - the shaft has a first diameter in the region of the radial bearing near the rotor, but has a wider or larger diameter than the first diameter in the region of the radial bearing far from the rotor; - and in that the fluid passage in the bearing element is fluidically connected to the radial bearings (4, 5) and the shaft projects through a portion of the fluid passage.