To provide a helicopter having a vibration damper that reduces airframe vibration during flight by suppressing resonance of a rotor and can improve ride comfort.

The helicopter 1 has a rotor having a blade 11 and a hub 13. The helicopter 1 comprises the vibration damper 15 having a first CFRP layer 16a disposed on the surface of a blade 11 and/or a hub 13, a second CFRP layer 16b disposed away from the first CFRP layer 16a by a predetermined interval, and an electroviscous fluid 17 filled into a space formed between the first CFRP layer 16a and the second CFRP layer 16b. A predetermined voltage is applied to the electroviscous fluid 17 via the first CFRP layer 16a and the second CFRP layer 16b. The vibration damper 15 further has a piezoelectric element 19 expanded and contracted with the applied voltage on the surface of the second CFRP layer 16b.