PURPOSE: To obtain a highly accurate automatic positioning method for a work and device therefore in an automatic magnetizer for a roll-shaped magnet which is designed to carry out an automatic or accurate alignment with a magnetization yoke or a magnetic force measuring sensor in a magnetization or magnetic force inspection device for a roll-shaped magnet.

CONSTITUTION: A shaft 6 of a roll-shaped magnet 1 on one side is loaded on a shaft receiver 2 while a shaft 7 on the other side is supported with a shaft temporary receiver 3 which can be vertically displaced. Then, a motor 17 is transferred to the axial direction of a roll-shaped magnet with a positioning spring 21 incorporated in an air chuck 4 fixed with a rotary shaft 18 of the motor 17, thereby depressing a shaft end face of the other shaft and engaging a shaft end face on one side with a positioning plane 11 of the shaft receiver 2. A shaft 7 on the other side is supported with a claw 20 of the air chuck 4 and then separated from the shaft by lowering the shaft temporary receiver 3.