Internal milling cutter

An internal milling cutter with an annular tool support which, on its inner lateral surface, is fitted with cutting inserts and is fastened in a machine holder comprising a bayonet connection between the tool support and the machine holder, wherein the bayonet connection comprises a strip-like annular body which contacts the tool support at one end, the strip-like annular body has protrusions at a side of the strip-like annular body which contacts the tool support, and the bayonet connection is screwed in a releasable manner to the tool support or the machine holder, and wherein groove guides are formed in the machine holder, and wherein the strip-like annular body has a plurality of radial projections on its outer lateral surface which are retained in the groove guides, and wherein the tool support has a protrusion which is guided in a groove-like recess formed by a first undercut formed in the strip-like annular body on its inner lateral surface and a second undercut opposite the first undercut formed in the machine holder.