A processing liquid nozzle according to an aspect of the present invention comprises an ultrasonic application part (60), a first supply flow path (71), a discharge flow path (72), and a second supply flow path (73). The ultrasonic application part (60) has a vibrator (61) for generating ultrasonic waves, and a vibrating body (62) joined to the vibrator (61). The first supply flow path (71) supplies a first liquid (L1) to a position contacting the vibrating body (62) of the ultrasonic application part (60). The discharge flow path (72) supplies the first liquid (L1), to which ultrasonic waves have been applied by the ultrasonic application part (60), to a discharge port (74). The second supply flow path (73) is connected to the discharge flow path (72) on the downstream side from the ultrasonic application part (60), and supplies a second liquid (L2) to the discharge flow path (72).