above in this operation however the sensor 65 provided on the rear portion of the stocker 2 detects the front end of the cartridge 1a inserted thereinto to terminate the energization of the motor 31 the cartridge 1a is held in place by holding springs 87 provided in the stocker 2 to prevent the cartridge from moving away from the shelf of the stocker 2 by abnormal vibration etc fig1 and 15 show another embodiment of the present invention in side and front views respectively in these figures a carrier 104 corresponding to the inserting and retrieving mechanism 4 in the preceding embodiment comprises an upper and lower carriers 131a and 131b having clampers 133a and 133b respectively the clampers 133a or 133b are shown in fig1 the clampers 133 are supported operably by a main shaft 106 and vertically movably by vertical sliders 107 slidably supported by a vertical guide rail 108 the rotation of the clampers 133 i e the turning thereof is performed by a motor 109 as shown in fig1 the clampers 133 are pivotably supported by pins 36 respectively front ends 135 of the clampers 133 serve as hooks and the other ends are rotatably hinged with one ends of links 137 constituting a toggle link the toggle link 137 are hinged with each other at the other ends thereof to which a plunger of a solenoid 134 is connected so that when the solenoid 134 is energized the clampers 133 are opened when the solenoid.