To provide an auxiliary member of a working helmet in which the helmet is supported by a part except a head only by attaching the auxiliary member to the helmet alone.

The auxiliary member 10 of the working helmet 100 that is worn in an up-looking operation includes a connection part 11 provided in a linked manner at the side of the back of the head 101 of the working helmet, a curved part 21 continuously extended from the connection part and a butt part 31 that is continued to the curved part and butted against a space between shoulders S of a superintendent M. When the superintendent looks up, the butt part is butted against the space between the shoulders and the working helmet in which the side of the back of the head is provided in a linked manner at the connection part is supported together with the head N of the superintendent through the curved part.