A centering device (1) for centering flat workpieces (700-706) comprises a centering station (100) having at least a first and a second gripping device (300, 301) for gripping the workpiece (700-706), and conveying means for conveying workpieces (700-706) in a conveying direction to the centering station (100). The first and the second gripping device (300, 301) can each be moved horizontally by a first and a second guiding device (200, 201), respectively, and the first and the second gripping device (300, 301) can rotate freely about an axis.