Provided is a curtain airbag apparatus capable of preventing a head of an occupant from being moved forward at the time of an oblique collision of the vehicle. To this end, a curtain airbag apparatus according to an exemplary embodiment of the present invention includes: an auxiliary airbag which is coupled to the curtain airbag, is inflated when gas flows into the auxiliary airbag, and protrudes into the interior of a vehicle; and a support panel which is coupled to the curtain airbag and the auxiliary airbag, and supports the protruding auxiliary airbag.