A curtain airbag device for a vehicle has a curtain airbag main body 17 that is disposed along a longitudinal direction of a vehicle body while covered with an A pillar trim 41 and roof trim 42, and folded in an A pillar 7 and a roof side rail part 30 of the vehicle body so as to be able to deploy downward within a cabin. The curtain airbag main body 17 is provided with a twisted part 17b that is twisted such that an initial deployment force, generated upon inflation and deployment of the curtain airbag main body 17 located in a vicinity of the A pillar trim 41, is acted in a separation direction in which the A pillar trim 41 is parted away from the A pillar part 7, to push open the A pillar trim 41 toward an inside of the cabin. At least an upper surface of the twisted part 17b is regulated by a supporting bracket 21 and disposed in the vehicle body.