Abstract: The present invention relates to a height-adjustable washstand comprising a cylinder 20 containing a piston 21 integrally coupled with a lifting rod 22 which can be moved by water pressure in a vertical direction, and a compression spring 23; solenoid valves SA, SB for simultaneously controlling an amount of water supplied through a water supplying pipe 31 branched from and flexibly connected to a water main 11, and an amount of water discharged through a water discharging pipe 32; and booster tanks DA, DB for moving the piston 21 of the cylinder 20 in a vertical direction by means of water pressure that is provided by the operation of solenoid valves SA, SB.