Provided is a functional headband having an integral cushion band that is applied to welding masks, protective masks, safety helmets, medical helmets, etc. The functional headband includes a main band configured to be worn on a wearer's head, supporting bands connected with the main band and configured to be placed on the wearer's head, adjustment bands connected with both ends of the main band and configured to be adjusted in length, a length adjustment lever configured to adjust the length of the adjustment bands, and cushion bands formed integrally at the supporting bands to cover the wearer's head, thereby supporting the wearer's head in a double supporting structure.