To obtain a helmet capable of moderating an uncomfortable feeling and a distraction of an attentive power, and also preventing a shield and goggles from clouding.

This helmet is installed with a solar cell 7 capable of generating an electricity for charging a battery 9. A wearer of the helmet e.g. under a hot climate in summer, can operate an operating unit not shown in the figure to switch on a controller 10 for applying a direct current electricity to a Peltier module 8 from the battery 9 to cool the inside of the helmet. Also, in the case that the temperature at the inside of the helmet becomes a suitable or a low temperature, the direct current electricity to the Peltier module 8 is cut by switching off the controller by operating the operating part. In this way, it is possible to set the temperature at the inside of the helmet as a suitable temperature to moderate an uncomfortable feeling and a distraction of an attentive power.