Disclosed herein is a two-layer vanity unit. The two-layer vanity unit includes: a cabinet; an upper vanity unit disposed on a top of the cabinet and exposed to the outside; a lower vanity unit disposed inside the cabinet so that it is selectively put into the cabinet when not in use and withdrawn from the cabinet when in use; drain pipes connected to the upper and lower vanity units; and cold and hot water pipes connected to the upper vanity unit. Control is performed to adjust one or more of water supply and water cutoff for the upper or lower vanity unit and an amount and temperature of the available water according to an operation mode of the lever of the faucet provided on the upper or lower vanity unit, thereby controlling a type of supply of available water.