An air spring device for a railcar body, comprising: an upper face plate; a lower face plate that is disposed facing the upper face plate; and a flexible membrane body that is resiliently coupled to the upper face plate and the lower face plate and that forms a pressurized space between the upper face plate and the lower face plate, the upper face plate and the lower face plate respectively including planar face portions (42, 44) that face each other, the planar face portion of the upper face plate being formed with a larger surface area than the planar face portion of the lower face plate, the upper face plate being provided with a limiting portion that is formed, with an outer side end edge of the planar face portion of the upper face plate as a starting end, so as to incline toward the lower face plate while extending away from a center side of the planar face portion of the upper face plate, characterized by, a first sloped face portion that is sloped with respect to the planar face portion of the upper face plate, the lower face plate including a second sloped face portion that is formed, with an outer side end edge of the planar face portion of the lower face plate as a starting end, so as to incline away from the upper face plate while extending away from a center side of the planar face portion of the lower face plate, and a resilient body and a support plate that are provided below the lower face plate, the lower face plate and the support plate being vertically coupled together by the resilient body. an upper face plate; a lower face plate that is disposed facing the upper face plate; and a flexible membrane body that is resiliently coupled to the upper face plate and the lower face plate and that forms a pressurized space between the upper face plate and the lower face plate, the upper face plate and the lower face plate respectively including planar face portions (42, 44) that face each other, the planar face portion of the upper face plate being formed with a larger surface area than the planar face portion of the lower face plate, the upper face plate being provided with a limiting portion that is formed, with an outer side end edge of the planar face portion of the upper face plate as a starting end, so as to incline toward the lower face plate while extending away from a center side of the planar face portion of the upper face plate, characterized by, a first sloped face portion that is sloped with respect to the planar face portion of the upper face plate, the lower face plate including a second sloped face portion that is formed, with an outer side end edge of the planar face portion of the lower face plate as a starting end, so as to incline away from the upper face plate while extending away from a center side of the planar face portion of the lower face plate, and a first sloped face portion that is sloped with respect to the planar face portion of the upper face plate, the lower face plate including a second sloped face portion that is formed, with an outer side end edge of the planar face portion of the lower face plate as a starting end, so as to incline away from the upper face plate while extending away from a center side of the planar face portion of the lower face plate, and a resilient body and a support plate that are provided below the lower face plate, the lower face plate and the support plate being vertically coupled together by the resilient body.