Provided are a device for producing a disposable wearable article and a method for producing a disposable wearable article capable of suppressing the occurrence of a sealing failure by making it difficult for a doubled sheet to open against an elastic force of an absorber. A device for producing a disposable wearable article includes a jointing/cutting unit (60) provided in a line (L1) for continuously conveying a sheet (W) and configured to join parts of the doubled sheet (W) at opposite sides of an absorber (C) and then cut the joined parts and a pressing unit (70) arranged upstream of the jointing/cutting unit (60) in a conveying direction (a). The pressing unit (70) includes a pressing mechanism (71, 72) configured to press the sheet (W) together with the absorber (C) in a thickness direction.