Airbag cover and airbag system

To provide a technique of constructing an airbag cover for covering the occupant side of a vehicle airbag, which is effective in increasing occupant restraining performance in a vehicle accident. An airbag cover 101 of an airbag system 100 has an airbag-cover flat surface 110 extending in such a way as to face the occupant, an uprising wall 120 uprising from the back of the airbag-cover flat surface 110 toward a mount portion on the vehicle side and fixed to the mount portion, and a tear line 102 formed in the airbag-cover flat surface 110 and the uprising wall 120, wherein when the vehicle airbag inflates, the airbag cover 101 is cleaved along the tear line 102 in the airbag-cover flat surface 110 and the uprising wall 120 to be divided into four airbag-cover divided pieces and is opened around the hinge of the uprising wall 120.