A positioning device for a wafer chuck, comprising: - a base, - a support present on the base, - a housing present on the support, in which there is under-pressure and which has a bottom, - a wafer chuck displaceable over the bottom in the housing and equipped with permanent magnets (29, 43 - 50), and - positioning means for positioning the wafer chuck and located underneath the bottom, which positioning means comprise at least six actuators (23, 37) for positioning the wafer chuck in six directions corresponding to six degrees of freedom, where from these actuators three vertical actuators position the wafer chuck in vertical direction and around two mutually perpendicular horizontal axes, and three horizontal actuators position the wafer chuck in two mutually perpendicular horizontal directions and around the vertical axis, - which vertical actuators each include gravity compensation means which comprise a disc-shaped round permanent magnet, as well as a coil and an annular permanent magnet having an opening in the middle, which annular magnet and which disc-shaped magnet are vertically polarized and the annular magnet is oppositely magnetized to the disc-shaped magnet, where: the inner diameter of the coil is larger than the outer diameter of the disc-shaped magnet, the outer diameter of the annular magnet is smaller than the outer diameter of the coil, and the inner diameter of the annular magnet is smaller than the inner diameter of the coil, characterized in that: - the coil is present partially around the disc-shaped round permanent magnet and partially present above it, such that the bottom of the coil is present at a level between the bottom and top (25A, 25B) of the disc-shaped magnet, the annular permanent magnet is present in the wafer chuck above the coil, and the outer diameter of the annular magnet is larger than the inner diameter of the coil. - a base, - a support present on the base, - a housing present on the support, in which there is under-pressure and which has a bottom, - a wafer chuck displaceable over the bottom in the housing and equipped with permanent magnets (29, 43 - 50), and - positioning means for positioning the wafer chuck and located underneath the bottom, which positioning means comprise at least six actuators (23, 37) for positioning the wafer chuck in six directions corresponding to six degrees of freedom, where from these actuators three vertical actuators position the wafer chuck in vertical direction and around two mutually perpendicular horizontal axes, and three horizontal actuators position the wafer chuck in two mutually perpendicular horizontal directions and around the vertical axis, - which vertical actuators each include gravity compensation means which comprise a disc-shaped round permanent magnet, as well as a coil and an annular permanent magnet having an opening in the middle, which annular magnet and which disc-shaped magnet are vertically polarized and the annular magnet is oppositely magnetized to the disc-shaped magnet, where: the inner diameter of the coil is larger than the outer diameter of the disc-shaped magnet, the outer diameter of the annular magnet is smaller than the outer diameter of the coil, and the inner diameter of the annular magnet is smaller than the inner diameter of the coil, characterized in that: - the coil is present partially around the disc-shaped round permanent magnet and partially present above it, such that the bottom of the coil is present at a level between the bottom and top (25A, 25B) of the disc-shaped magnet, the annular permanent magnet is present in the wafer chuck above the coil, and the outer diameter of the annular magnet is larger than the inner diameter of the coil.