For a flexible fastening, a fastening device for fastening a column to a support device comprises: a column plate which can be fastened to one end of the column and an accommodation device which can be fastened to the support device. The accommodation device has a longitudinal shape with a longitudinal direction and a predetermined length in the longitudinal direction and a cross-section, whereby an accommodation space configured to accommodate the column plate in a manner shiftable in the longitudinal direction and in an exactly fitting manner in the direction perpendicular to the longitudinal direction is formed. The fastening device comprises a fastening member configured to fasten the column plate to the accommodation device along the longitudinal direction, and, in the longitudinal direction, the column plate has a dimension which is smaller than the predetermined length in a state mounted in the fastening device.