A sample holder for fixing and transporting a sample vial (1) within an NMR configuration comprising an outer shell (4) and a continuous hollow space disposed inside the outer shell (4) and extending along its axis for receiving the sample vial, is characterized in that a clamping device that can be switched on and off and a switching element (6) are provided inside the hollow space, wherein, in the activated state, the clamping device fixes a sample vial (1) that is introduced into the sample holder, the switching element (6) can be operated from the outside, and the clamping device can be deactivated using the switching element (6) such that, in the deactivated state, the sample vial (1) inserted into- or removed from the sample holder is not fixed. Such a sample holder may be used to realize an automatic supply device for changing NMR sample vials which has a very compact structure and can be mounted using little space.