According to a passenger airbag apparatus according to an exemplary embodiment of the present invention, a left chamber portion and a right chamber portion protrude forward at a front side of an airbag so as to be spaced apart from each other in a left and right direction, and a groove tether pulls the front side of the airbag between the left chamber portion and the right chamber portion, and as a result, a groove is formed at the front side of the airbag between the left chamber portion and the right chamber portion.