An airbag apparatus, comprising a bag shaped cushion (200, 220, 240, 260, 280) which is configured to be installed in a vehicle and to expand and deploy in front of a seat from the front towards the rear of the vehicle; the cushion comprising: a front restraining part which restrains the head of a passenger from the front of a vehicle; and at least one protrusion part (124, 126) which is provided beside the front restraining part in the width direction of the vehicle and is capable of protruding and expanding further towards the rear of the vehicle than the front restraining part; the airbag apparatus further comprising, inside the cushion: at least one inner tether (130, 132, 202, 204) having a rear end which is connected to the front restraining part and to which tension is applied to pull the front restraining part towards the front of the vehicle; and an outer tether (134, 136, 242, 244, 262, 264) having a rear end (140, 248, 266, 268) connected to the protrusion part and to which tension is applied to pull the protrusion part (124, 126) towards the front of the vehicle; wherein when tension is applied to the inner tether (130, 132, 202, 204), so as to pull the front restraining part towards the front of the vehicle, the outer tether (134, 136, 242, 244, 262, 264) is also pulled to the inner tether (130, 132, 202, 204) side via the front restraining part, with the force towards the inner tether (130, 132, 202, 204) side applied to the outer tether (134, 136, 242, 244, 262, 264), characterized in that upon completion of the expansion and deployment of the cushion (200, 220, 240, 260, 280), the length of the inner tether (130, 132, 202, 204) is set to be shorter than the outer tether (134, 136, 242, 244, 262, 264) such that the rear end of the inner tether (130, 132, 202, 204) is positioned closer to the front of the vehicle than the rear end (140, 248, 266, 268) of the outer tether, such that the application of tension to the inner tether (130, 132, 202, 204) is completed prior to applying tension to the outer tether (134, 136, 242, 244, 262, 264). a front restraining part which restrains the head of a passenger from the front of a vehicle; and at least one protrusion part (124, 126) which is provided beside the front restraining part in the width direction of the vehicle and is capable of protruding and expanding further towards the rear of the vehicle than the front restraining part; the airbag apparatus further comprising, inside the cushion: at least one inner tether (130, 132, 202, 204) having a rear end which is connected to the front restraining part and to which tension is applied to pull the front restraining part towards the front of the vehicle; and an outer tether (134, 136, 242, 244, 262, 264) having a rear end (140, 248, 266, 268) connected to the protrusion part and to which tension is applied to pull the protrusion part (124, 126) towards the front of the vehicle; wherein when tension is applied to the inner tether (130, 132, 202, 204), so as to pull the front restraining part towards the front of the vehicle, the outer tether (134, 136, 242, 244, 262, 264) is also pulled to the inner tether (130, 132, 202, 204) side via the front restraining part, with the force towards the inner tether (130, 132, 202, 204) side applied to the outer tether (134, 136, 242, 244, 262, 264), at least one inner tether (130, 132, 202, 204) having a rear end which is connected to the front restraining part and to which tension is applied to pull the front restraining part towards the front of the vehicle; and an outer tether (134, 136, 242, 244, 262, 264) having a rear end (140, 248, 266, 268) connected to the protrusion part and to which tension is applied to pull the protrusion part (124, 126) towards the front of the vehicle; wherein when tension is applied to the inner tether (130, 132, 202, 204), so as to pull the front restraining part towards the front of the vehicle, the outer tether (134, 136, 242, 244, 262, 264) is also pulled to the inner tether (130, 132, 202, 204) side via the front restraining part, with the force towards the inner tether (130, 132, 202, 204) side applied to the outer tether (134, 136, 242, 244, 262, 264),