Abstract: A water distiller includes a raw water chamber for storing raw water, a main vaporization tank coupled with the raw water chamber for vaporizing raw water, a condensation device coupled with the main vaporization tank for condensing steam from the main vaporization tank, and a distilled water chamber communicated with the condensing conduit unit for accepting and storing distilled water. An auxiliary vaporization tank is communicated with the main vaporization tank and is mounted on the top end portion of the main vaporization tank. Each of the main and auxiliary vaporization tanks has a generally conical top wall which has a lower end portion that is provided with an annular water collecting groove formed in the inner surface thereof. Each of the water collecting grooves has a bottom wall which has a discharge opening formed therethrough.