To provide an airbag and an airbag device that is excellent in an impact absorbing force and can efficiently inflate and deploy the airbag. An airbag 1 according to the present invention includes a left inflation chamber 11L that is inflated and deployed on the front left side of a passenger P and a right inflation chamber 11R that is inflated and deployed on the front right side of the passenger P. The left inflation chamber 11L and the right inflation chamber 11R include a first communication path 12 formed at an end portion on the car body side, a connection portion 13 connected at an intermediate portion in the inflating and deploying direction, and a second communication path 14 formed within the connection portion 13. The airbag further includes a first tether 3 having one end connected to each inner face of the left inflation chamber 11L and the right inflation chamber 11R and the other end connected into the connection portion 13 and a second tether 4 having one end connected the inner faces in the vicinity of top portions of the left inflation chamber 11L and the right inflation chamber 11R and the other end connected into the connection portion 13.