Airbag and airbag device provided with the airbag

An airbag comprising:

• an airbag main body that is provided with a gas introduction opening of an inflation gas;
• and
• an inner cloth portion that is mounted and fixed so as to cover the gas introduction opening in the airbag main body, the airbag main body being caused to inflate and expand by the inflation gas,
• wherein the inner cloth portion comprises:
• a first opening end part at which one end in a lengthwise direction opens as a gas outflow opening;
• and
• a second opening end part at which the other end in the lengthwise direction opens as a gas outflow opening,
• wherein a mounting and fixing portion of the inner cloth portion is fixed to a circumferential edge part of the gas introduction opening of the airbag main body while a position of the inner cloth portion is superimposed with the gas introduction opening of the airbag main body, and
• wherein the first opening end part and the second opening end part of the inner cloth portion is folded in a predetermined procedure together with the airbag main body in a state in which the first and second end parts are sandwiched between base cloths constituting the airbag main body.