PURPOSE: To have smooth transfer of a tool to a spindle by furnishing a rotary tool magazine of cartridge accommodation type, which has ability to accommodate tools in high density, and a device which is to transport a tool socket.

CONSTITUTION: A disc type tool magazine 23 includes a base 23a in the form of a disc to accommodate eight radially arranged cartridges 25, each of which accommodates three tool sockets 27 removably. This magazine base 23a is equipped in its center with a cylindrical inner wall 61 and an inner gear 63, and two of its surfaces 65, 67 in the thickness direction are formed flatly. Each cartridge 25 is formed in a lightweight frame provided at its lateral side-face with openings 40 in longitudinal arrangement, wherein three openings 40 serve as mounting/demounting holes for accommodating three tool sockets 27 removably together with tool. A tool socket transport device serves hand-over of a tool socket 27 having desired tool, pulling-out from cartridge 25 and transport to the tool exchange position.