A portable ultrasonic mist generator is composed of a liquid storing tank (1), an ultrasonic vibrator (2), a transmission film (3) which transmits ultrasonic waves, and a packing (9) arranged between the liquid storing tank (1) and the ultrasonic vibrator (2). A blocking board (10) having many pyramidal or conical protruding sections (11) formed on an upper surface thereof is arranged above the packing (9) or the ultrasonic vibrator (2). Thus, reflected waves (15) of ultrasonic waves (6) are diffused, absorbed and blocked by the protruding sections (11) and the blocking board (10), and the reflected waves do not reach the packing (9).
