In order to provide a light weight anvil roller and an ultrasonic welding device provided therewith this anvil roller (10) is provided with: a supported part (19) which is rotatably supported by a holding mechanism (11) via a rotation shaft (12a) such that the anvil roller (10) can come into rotating contact with a sheet (W) an outer peripheral part (18) having a welding surface for welding the sheet (W) between said outer peripheral part (18) and an ultrasonic horn (6) while in rolling contact with the sheet (W) a thin part (21) which is formed such that the axial thickness of the rotation shaft (12a) between the supported part (19) and the outer peripheral part (18) is less than the thickness of the outer peripheral part (18) and an anti vibration member (22) provided on the thin part (21).
