Demagnetize a variety of magnetic metal and the work piece with magnetic surface. Demagnetize press molds and injection molds. Demagnetize a narrow space. It is a portable demagnetizer. Directly enter a narrow slit or a dead angle for demagnetizing. Demagnetize the mold(s) on the machine without dismantling the mold(s), especially for the mold(s) under continuous pressing. It reduces metal chips or fine metal powder absorbed by magnetic field, and avoids the mold being damaged.