The present invention relates to a method of fabricating an organic structure directing agent-free CHA type zeolite membrane and a membrane fabricated thereby, and more particularly to a method of fabricating a continuous CHA type zeolite membrane, which exhibits CO2/N2 and CO2/CH4 separation performances comparable with those of conventional membranes, in a cost-effective manner without a calcination process by hydrothermal synthesis using an alkali metal hydroxide without using an organic structure directing agent, and to a membrane fabricated thereby.