To provide an adjusting method of attraction weight with a lifting magnet that can accurately adjust the weight of magnetic material such as scrap material attracted to the lifting magnet to a target weight in a high efficiency.
The output voltage of a lifting magnet is set at the maximum value VH. A magnetic material of a weight WE exceeding a target weight S is attracted and suspended. Then, the output voltage is quickly decreased in a steep gradient pattern V1A, and the magnetic force is quickly decreased. Thus, the magnetic material is quickly dropped from the lifting magnet. After the attracted weight has reached a specified switching weight WK exceeding the target weight S, the output voltage is dropped at a less gradient pattern V1B, and the magnetic force is gradually decreased. Thus, the magnetic material is gradually dropped from the lifting magnet. When the attracted weight of the magnetic material has reached the target weight S, the output voltage is immediately returned to the maximum value VH, and the dropping of the magnetic material is blocked.