invention for determining a deformation of a disc shaped workpiece according to fig1 a f as is shown by fig1 g the mould wafer 3 is deformed in a downward direction at all points p 1 p 8 shown in comparison to the predetermined height position z 0 and also has a cap like shape with reference to fig1 c it is likewise possible to adjust the detector unit 50 in the radial direction with respect to the mould wafer 3 in order to adopt a height profile of the type shown in fig1 g at various circumferences ku having various radii r fig2 is a flow diagram of a further embodiment of the method according to the invention for determining a deformation of a disc shaped workpiece particularly a mould wafer in a method step not shown calibration of the device is carried out using an ideal wafer 3 as shown in fig1 c for calibration the support pins 11 a 11 b 11 c can in particular be adjusted in such a way that the ideal mould wafer is positioned having its lower face u exactly at the predetermined height position z 0 with reference to step s 1 the mould wafer 3 is subsequently fitted to the support pins 11 a 11 b 11 c of the contact elements 15 a 15 b 15 c and is subsequently mounted by actuating the vacuum intake elements 20 a 20 b 20 c.