We have developed an energy-saving technology for purifying biobutanol. It uses a kind of zeolite membrane and can recover concentrated 1-butanol (hereinafter referred to as butanol) of at least 80 wt% from dilute (about 1 wt%) aqueous butanol solution. Butanol has a larger calorific value than ethanol. It is expected to be a post-bioethanol fuel, namely a renewable liquid biofuel that is useful in mitigating global warming. A silicalite membrane that has high permselectivity for butanol was synthesized through the optimization of hydrothermal synthesis conditions. The membrane enables the recovery of highly concentrated butanol from low-concentration aqueous solutions of butanol by pervaporation separation. Its use is expected to reduce drastically the energy required to recover butanol by separation membrane methods. Use of this membrane would contribute to the further development of butanol production technologies and effective use of biomass.