To eliminate problems that perspiration in a head part during operation is unpleasant and the operating efficiency is lowered.

A perspiration absorbing member is detachable from an auxiliary band for a helmet. Furthermore, the auxiliary band is detachable from a head band on the inside of the helmet body. Attaching parts are formed at both ends in the longitudinal direction of the auxiliary band and engaged with engaging parts formed in both temple parts of the head band to thereby make the auxiliary band detachable from the head band. The attaching positions for the auxiliary band to the head band can be regulated by changing the engaging positions. The auxiliary band is slender and has a width. An upper edge and a lower edge thereof are curved in one of the width directions. The auxiliary band is formed into a fan-shaped state from the upper edge toward the lower edge so as to pass along the curved surface of the forehead of a user. The perspiration absorbing member is formed into a cylindrical form for passing the auxiliary band therethrough and attaching the auxiliary band. The perspiration absorbing member is freely detachable from the auxiliary band and can freely be exchanged with the auxiliary band. The helmet is obtained by detachably attaching the auxiliary band to the head band.