Holding device for holding a calibrating element which, for calibrating a measuring sensor of a coordinate measuring machine, can be scanned by the measuring sensor, wherein • the holding device has an adjusting mechanism (11, 19), which is designed to adjust an alignment of a calibrating element held on the holding device by being actuated by a user, • the adjusting mechanism (11, 19) has a rotatable part, which is rotatable with respect to another part of the adjusting mechanism (11, 19) about a first axis of rotation, the calibrating element being connected to the rotatable part for its attachment to the holding device, • the holding device has a rod-shaped attachment element, to which the calibrating element can be attached, the rod-shaped attachment element being connected to the rotatable part in order to attach the calibrating element to the holding device, so that an alignment of the calibrating element is defined by the alignment of the longitudinal axis of the rod-shaped attachment element and so that an alignment of the calibrating element can be adjusted by a turning of the rotatable part of the holding device about the first axis of rotation, • the holding device is designed in such a way that at least a part of the holding device is rotatable about a second axis of rotation, which intersects the first axis of rotation at an angle or extends obliquely in relation to the first axis of rotation, so that the alignment of the calibrating element is adjustable by turning movements about the first axis of rotation and the second axis of rotation, • with appropriate arrangement of the holding device, for example on a measuring table, the second axis of rotation extends in a vertical direction and the first axis of rotation is inclined with respect to the vertical. • the holding device has an adjusting mechanism (11, 19), which is designed to adjust an alignment of a calibrating element held on the holding device by being actuated by a user, • the adjusting mechanism (11, 19) has a rotatable part, which is rotatable with respect to another part of the adjusting mechanism (11, 19) about a first axis of rotation, the calibrating element being connected to the rotatable part for its attachment to the holding device, • the holding device has a rod-shaped attachment element, to which the calibrating element can be attached, the rod-shaped attachment element being connected to the rotatable part in order to attach the calibrating element to the holding device, so that an alignment of the calibrating element is defined by the alignment of the longitudinal axis of the rod-shaped attachment element and so that an alignment of the calibrating element can be adjusted by a turning of the rotatable part of the holding device about the first axis of rotation, • the holding device is designed in such a way that at least a part of the holding device is rotatable about a second axis of rotation, which intersects the first axis of rotation at an angle or extends obliquely in relation to the first axis of rotation, so that the alignment of the calibrating element is adjustable by turning movements about the first axis of rotation and the second axis of rotation, • with appropriate arrangement of the holding device, for example on a measuring table, the second axis of rotation extends in a vertical direction and the first axis of rotation is inclined with respect to the vertical.