An embodiment of a circular, annular tool magazine shelf of a tower construction, comprises a base frame adapted for receiving a tool shelf which has a plurality of immovable tool deposit plates, arranged in vertical succession and in a circular ring, adapted for machining one or more tools, and a power-driven tool handling system adapted for transporting tools between the tool magazine shelf and a machine-side pick-up tool magazine store. The magazine shelf also comprises a spindle tower which is mounted rotatably about a vertical rotation shaft being arranged in a circle center-point of one or more tool deposit plates, wherein the base frame includes a monolithically constructed, plate-shaped foundation in which the rotation shaft is mounted overhanging freely by way of a mounting arrangement.