A water treatment device comprising: a filtration part including at least one water filter to filter water supplied from a water supply source; a storage part storing the water filtered by the filtration part; a discharge part including a discharge member externally discharging the water stored in the storage part; a sterilizing part producing sterilization water, using water filtered by at least one water filter in the filtration part, to sterilize the storage part and the discharge part with sterilization water, wherein the sterilization part includes a sterilization water producing unit configured to dissolve a sterilizing material in the received filtered water to produce sterilization water or configured to electrolyze the received filtered water to produce sterilization water and wherein the sterilization water production unit is connected to the storage part by a sterilization water supply line; and a sterilization water discharge device comprising a tray part movably provided below the discharge member through which water is discharged, and configured to receive sterilization water discharged from the discharge member to drain the sterilization water, and a movement driving part configured to move the tray part, and wherein the tray part moves between a standby position, in which water other than the sterilization water, discharged from the discharge member, is not provided to the tray part, and a sterilization water drainage position, in which the sterilization water, discharged from the discharge member is provided to the tray part, and wherein the tray part is provided with a sterilization water receiving portion formed therein, the sterilization water receiving portion having an open upper portion through which the sterilization water discharged from the discharge member is provided, and is provided with a drainage port connected to the sterilization water receiving portion to drain the sterilization water contained in the sterilization water receiving portion. a filtration part including at least one water filter to filter water supplied from a water supply source; a storage part storing the water filtered by the filtration part; a discharge part including a discharge member externally discharging the water stored in the storage part; a sterilizing part producing sterilization water, using water filtered by at least one water filter in the filtration part, to sterilize the storage part and the discharge part with sterilization water, wherein the sterilization part includes a sterilization water producing unit configured to dissolve a sterilizing material in the received filtered water to produce sterilization water or configured to electrolyze the received filtered water to produce sterilization water and wherein the sterilization water production unit is connected to the storage part by a sterilization water supply line; and a sterilization water discharge device comprising a tray part movably provided below the discharge member through which water is discharged, and configured to receive sterilization water discharged from the discharge member to drain the sterilization water, and a movement driving part configured to move the tray part, and wherein the tray part moves between a standby position, in which water other than the sterilization water, discharged from the discharge member, is not provided to the tray part, and a sterilization water drainage position, in which the sterilization water, discharged from the discharge member is provided to the tray part, and wherein the tray part is provided with a sterilization water receiving portion formed therein, the sterilization water receiving portion having an open upper portion through which the sterilization water discharged from the discharge member is provided, and is provided with a drainage port connected to the sterilization water receiving portion to drain the sterilization water contained in the sterilization water receiving portion. a sterilization water discharge device comprising a tray part movably provided below the discharge member through which water is discharged, and configured to receive sterilization water discharged from the discharge member to drain the sterilization water, and a movement driving part configured to move the tray part, and wherein the tray part moves between a standby position, in which water other than the sterilization water, discharged from the discharge member, is not provided to the tray part, and a sterilization water drainage position, in which the sterilization water, discharged from the discharge member is provided to the tray part, and wherein the tray part is provided with a sterilization water receiving portion formed therein, the sterilization water receiving portion having an open upper portion through which the sterilization water discharged from the discharge member is provided, and is provided with a drainage port connected to the sterilization water receiving portion to drain the sterilization water contained in the sterilization water receiving portion.