Abstract: Equipment for melting a used injection needle includes a pair of movable contacts (2) and a fixed contact (3) between which electric voltage is applied. A short-circuit detector (4), determines when the movable contacts (2) and the fixed contact (3) are short-circuited by a used injection needle (9), and a timer (5) produces a signal during the period in which the short-circuit detector (4) produces a signal. An electromagnet drives the movable contacts (2) together to secure the used injection needle (9) to decrease the contact resistance between the movable contacts (2) and the used injection needle (9) and to allow a large electric current to flow in the used injection needle (9) in a stable manner.