A pedestrian protection airbag device, comprising: an airbag cushion that expands and deploys from below a front hood of a vehicle toward a windshield and includes a back surface side panel at least contacting the windshield and a front surface side panel on an opposite side from the back surface side panel; and an inflator (112a,112b) that supplies gas to the airbag cushion; wherein the airbag cushion includes: a main expansion part covering at least a lower part of the windshield from one of a pair of A-pillars (110a,110b) to the other of the pair of A-pillars (110a,110b) in the vehicle; and a pair of protruding expansion parts (120a,120b) protruding upward from the main expansion part along each of the pair of A-pillars (110a,110b), so as to cover the A-pillars (110a,110b), the main expansion part includes a first main expansion part and a second main expansion part, which are divided into left and right sections so as to be mutually adjacent at an intermediate position in a vehicle width direction of the vehicle, characterized in that the airbag cushion further includes a high friction part (124,200,220) formed in a range that at least includes the vicinity of an end part of the front surface side panel of each of the first main expansion part and second main expansion part at an intermediate position in the vehicle width direction and which has a higher coefficient of friction than another outer front surface of the airbag cushion, wherein the high friction part (124,200,220) is further formed in a range that includes the vicinity of an end part of the intermediate position of the back surface side panel in the vehicle width direction, wherein the high friction part (124,200,220) is further formed on each end surface part of the first main expansion part and the second main expansion part facing each other at the intermediate position, wherein the high friction part (124,200,220) has a smaller dimension in the vehicle width direction than the dimension in the front-rear direction, wherein the main expansion part is divided into the first main expansion part and second main expansion part, thereby forming a valley.at a center position in vehicle width direction, wherein the high friction part (124,200,220) is formed in a region in the vicinity of the valley at the center position in the vehicle width direction of the front surface side panel. a main expansion part covering at least a lower part of the windshield from one of a pair of A-pillars (110a,110b) to the other of the pair of A-pillars (110a,110b) in the vehicle; and a pair of protruding expansion parts (120a,120b) protruding upward from the main expansion part along each of the pair of A-pillars (110a,110b), so as to cover the A-pillars (110a,110b), the main expansion part includes a first main expansion part and a second main expansion part, which are divided into left and right sections so as to be mutually adjacent at an intermediate position in a vehicle width direction of the vehicle, characterized in that the airbag cushion further includes a high friction part (124,200,220) formed in a range that at least includes the vicinity of an end part of the front surface side panel of each of the first main expansion part and second main expansion part at an intermediate position in the vehicle width direction and which has a higher coefficient of friction than another outer front surface of the airbag cushion, wherein the high friction part (124,200,220) is further formed in a range that includes the vicinity of an end part of the intermediate position of the back surface side panel in the vehicle width direction, wherein the high friction part (124,200,220) is further formed on each end surface part of the first main expansion part and the second main expansion part facing each other at the intermediate position, wherein the high friction part (124,200,220) has a smaller dimension in the vehicle width direction than the dimension in the front-rear direction, wherein the main expansion part is divided into the first main expansion part and second main expansion part, thereby forming a valley.at a center position in vehicle width direction, wherein the high friction part (124,200,220) is formed in a region in the vicinity of the valley at the center position in the vehicle width direction of the front surface side panel.