PURPOSE: To hold a tool with high reliability without heating due to long-time use by providing a portable drill support removably fitted to a steel frame of a building or the like with a permanent-electromagnet attaching unit having a nonreversible magnetic core and a reversible magnetic core.

CONSTITUTION: This drill support is so constructed that the base is provided with a permanent-electromagnet attaching unit (PE unit) 6. The PE unit 6 is formed by alternately arranging reversible permanent magnets 11 having coils 13 and nonreversible permanent magnets like checkers, and the respective rows of the magnets 11, 14 are separated from each other by soft steel pole pieces 15. The whole of the array is covered with a top plate made of non-magnetic material such as aluminum or the like. When the switch of the device is turned on, the row of the nonreversible permanent magnet 14 is magnetized in the same direction as that of the nonreversible permanent magnets 11, whereby the base of the drill support is magnetized and fixed to a part to be worked, and the magnetized fixed state is released by turning off the switch.