To provide an ultrasonic-wave cleaning nozzle which is used for ultrasonic cleaning of a substrate to be cleaned, is of a laterally long shower type and can quickly remove bubbles in the nozzle with a little cleaning liquid to uniformly discharge the cleaning liquid.

The ultrasonic-wave cleaning nozzle is used for ultrasonic cleaning of the substrate, has at least a spraying chamber with a shape of laterally long trapezoid inside, which has a nozzle body with an opened discharging opening of a shape of slit at an end, an oscillator and a diaphragm, wherein the nozzle body has an introduction passage for supplying the cleaning liquid to the spraying chamber and a plurality of straightening passages which communicates the introduction passage with the spraying room, are formed at equivalent intervals at the side of the spraying chamber and have a circular section. In the cleaning nozzle, the flowing velocity (v) of the cleaning liquid flowing through the straightening passages which is calculated from the horizontal length (W) of the discharging opening, the diameter (d) of the straightening passages, the interval (L) of each straightening passage and the total flowing amount (Q) of the cleaning liquid, satisfies v=100 LQ/(3 πWd2)≥1.8 m/sec.