Adjusting mechanism of a sample holder comprising: - a base with drives (5.1 to 5.3) arranged thereon, wherein a first drive (5.1) has a first drive spindle (5.11) extending along a first drive axis (5.1A), a second drive (5.2) has a second drive spindle (5.21) extending along a second drive axis (5.2A) and a third drive (5.3) has a third drive spindle (5.31) extending along a third drive axis (5.3A), - a carrier, which is adjustable by means of the drives (5.1 to 5.3) and is designed to receive the sample holder, - for each drive (5.1 to 5.3) a coupling element (4.1 to 4.3), which is designed to connect base and carrier, wherein each coupling element (4.1 to 4.3) has both at least one linear degree of freedom and also at least one rotary degree of freedom, - the carrier is linearly movable along a respective movement axis (A1, A2, A3) directed from the coupling element (4.1, 4.2, 4.3) to the carrier, characterized in that - the carrier is adjustable, by means of the driven coupling elements (4.1 to 4.3), in the direction of each of the axes of a Cartesian system of coordinates and - the movement axes (A1, A2, A3) intersect virtually at a pivot point of the carrier, and - the connection of the coupling element (4.1, 4.2, 4.3) to the carrier is formed by means of a bolt movable along the movement axis (A1, A2, A3), wherein the bolt is mounted in a ball joint which is present at the carrier-side end of the drive spinde (5.11) and is mounted there in a bore which extends through the ball joint and the bolt engages with one of its ends in a bore in an end face of the carrier and the bolt is mounted so as to be movable along its longitudinal axis (12.1) in the bore of the ball joint and/or in the bore of the carrier. - a base with drives (5.1 to 5.3) arranged thereon, wherein a first drive (5.1) has a first drive spindle (5.11) extending along a first drive axis (5.1A), a second drive (5.2) has a second drive spindle (5.21) extending along a second drive axis (5.2A) and a third drive (5.3) has a third drive spindle (5.31) extending along a third drive axis (5.3A), - a carrier, which is adjustable by means of the drives (5.1 to 5.3) and is designed to receive the sample holder, - for each drive (5.1 to 5.3) a coupling element (4.1 to 4.3), which is designed to connect base and carrier, wherein each coupling element (4.1 to 4.3) has both at least one linear degree of freedom and also at least one rotary degree of freedom, - the carrier is linearly movable along a respective movement axis (A1, A2, A3) directed from the coupling element (4.1, 4.2, 4.3) to the carrier, - the carrier is adjustable, by means of the driven coupling elements (4.1 to 4.3), in the direction of each of the axes of a Cartesian system of coordinates and - the movement axes (A1, A2, A3) intersect virtually at a pivot point of the carrier, and - the connection of the coupling element (4.1, 4.2, 4.3) to the carrier is formed by means of a bolt movable along the movement axis (A1, A2, A3), wherein the bolt is mounted in a ball joint which is present at the carrier-side end of the drive spinde (5.11) and is mounted there in a bore which extends through the ball joint and the bolt engages with one of its ends in a bore in an end face of the carrier and the bolt is mounted so as to be movable along its longitudinal axis (12.1) in the bore of the ball joint and/or in the bore of the carrier.