Disclosed herein is a high-efficiency acoustic wave generator using a pulsed thermal radiation beam. The generator is configured such that when a pulse beam formed by a light interrupter is directly radiated onto a porous material having a woven net or steel scrubber shape, thin wires of the porous material repeatedly rapidly thermally-expand and contract, whereby air in the space between the wires is momentarily heated and cooled, and the expansion and contraction of air is directly transmitted to an air column formed just adjacent to the porous material. By virtue of the above structure, the efficiency of the generator is markedly improved compared to the conventional technique, and the productivity is also greatly enhanced.
