β-Zeolites are synthesized by using a directing agent prepared by dissolving an Al salt (preferably NaAlO 2 ) in an aqueous solution containing a tetraethylammonium hydroxide (TEAOH) template and NaOH and adding activated SIO 2 . The directing agent has a composition expressed in terms of oxide mol ratios:SiO 2 Al 2 O 3 = 20-120, TEAOH/SiO 2 = 0.2-0.5,Na 2 OSiO 2 = 0.04-0.10, and H 2 OSiO 2 = 7.5-25; the directing agent is prepared at 15-70°C followed by aging at 50-150°C. In the manufacture of β-zeolites, the volume ratio of the directing agent to the raw material mixture is 0.5-10%.