PROBLEM TO BE SOLVED: To make positional deviation between a welding part of a forward path and a welding part of a backward path formed in a prescribed section inconspicuous in a case of performing ultrasonic welding processing.SOLUTION: An ultrasonic welding apparatus 20 includes a rotary member 30 and an ultrasonic processing unit 60 which rotates around a central axis together with the rotary member. In a prescribed section of a CD direction on an outer peripheral surface of the rotary member, both a horn 61 and an anvil 71 are brought into contact with a sheet-like member 1a in the forward path and the backward path of the reciprocation movement. The ultrasonic welding apparatus includes an ultrasonic energy adjustment section which makes ultrasonic energy input per unit length in the CD direction in the prescribed section of the forward path and ultrasonic energy input per unit length in the CD direction in the prescribed section of the backward path different from each other.【課題】超音波溶着処理を行う場合に、所定区間で形成される往路の溶着部と復路の溶着部との位置ずれを目立たなくする。【解決手段】超音波溶着装置２０で、回転部材３０と、前記回転部材と一緒に中心軸回りに回転する超音波処理ユニット６０とを備える。前記回転部材の前記外周面におけるＣＤ方向の所定区間では、往復移動の往路及び復路の両方においてホーン６１とアンビル７１との両者はそれぞれシート状部材１ａに当接している。往路の前記所定区間においてＣＤ方向の単位長さ当たりに投入される超音波エネルギーと、復路の前記所定区間においてＣＤ方向の単位長さ当たりに投入される超音波エネルギーを互いに異ならせる超音波エネルギー調整部を有している。【選択図】図３
