To provide a chain with an attachment allowing easy mounting/ removing of the attachment and stabilizing the mounted attachment without removing the attachment, in the chain with the attachment mounted with the attachment by being engaged to pins projecting from both sides of the chain.

The shape of the attachment is formed into a substantial U- shape constituted of an upper plate and a leg part. The leg part has a pair of an outer claw and an inner claw. At the boundary of the outer claw and the inner claw, an engagement groove fitted with the pins therein is provided. An entrance width of the engagement groove is narrowed and a slit groove is formed at the bottom. At the center of the leg part, a cut-out part is provided. By engaging the engagement groove to the pins, the attachment is stably mounted.