A liquid dispensing device, comprising: a housing disposed inside of a distillation column; lattice -shaped upper and lower grids (120a, 120b) which are disposed at the inner sides of top and bottom of the housing; a collector tray disposed at top of the inner side of the housing for thereby guiding the liquid inputted through the upper grid; a porous plate which is disposed at top of the collector tray and includes a plurality of through holes through which the guided liquid descends; a dispensing box which is disposed at a lower side of the porous plate and is configured to dispense the liquid which descends through the porous plate, through an outlet tube connected to both sides thereof to the outside of the housing; a liquid dispenser which is disposed at a lower side of the dispensing box and is configured to uniformly dispense and discharge the liquid dispensed by the dispensing box toward the lower side; a connection tube connected to enable a fluid flow between the dispensing box and the liquid dispenser; an inlet tube configured to enable a liquid input from the outside of the housing to the liquid dispenser; and a separation wall which is vertically disposed at a lower side of the housing for thereby bisecting the lower space of the housing into a first chamber and a second chamber, wherein the dispensing box comprises: a box body which is formed in a rectangular parallelepiped shape and whose top is open; a first unit partition which is disposed inside of the box body and is configured to divide the inner side of the box body into a first unit chamber and a second unit chamber; and a second unit partition which is configured to interconnect the first unit partition and the inner wall of the box body for thereby forming a unit separation space, wherein the height of the first unit partition is lower than the height of the box body, and the height of the second unit partition is lower than the height of the first unit partition, wherein the outlet tube is connected to discharge the liquid in the unit separation space to the outside, and wherein the outlet tube is connected to the inlet tube in such a way to enable the discharged liquid to enter the liquid dispenser, wherein the liquid which has descended into the dispensing box is inputted through the top of the second unit partition into the space formed between the first unit partition and the second unit partition and is discharged through the outlet tube to the outside, and wherein a discharge of the liquid is controlled by adjusting the opening and closing of the valve installed at the outlet tube. a housing disposed inside of a distillation column; lattice -shaped upper and lower grids (120a, 120b) which are disposed at the inner sides of top and bottom of the housing; a collector tray disposed at top of the inner side of the housing for thereby guiding the liquid inputted through the upper grid; a porous plate which is disposed at top of the collector tray and includes a plurality of through holes through which the guided liquid descends; a dispensing box which is disposed at a lower side of the porous plate and is configured to dispense the liquid which descends through the porous plate, through an outlet tube connected to both sides thereof to the outside of the housing; a liquid dispenser which is disposed at a lower side of the dispensing box and is configured to uniformly dispense and discharge the liquid dispensed by the dispensing box toward the lower side; a connection tube connected to enable a fluid flow between the dispensing box and the liquid dispenser; an inlet tube configured to enable a liquid input from the outside of the housing to the liquid dispenser; and a separation wall which is vertically disposed at a lower side of the housing for thereby bisecting the lower space of the housing into a first chamber and a second chamber, wherein the dispensing box comprises: a box body which is formed in a rectangular parallelepiped shape and whose top is open; a first unit partition which is disposed inside of the box body and is configured to divide the inner side of the box body into a first unit chamber and a second unit chamber; and a box body which is formed in a rectangular parallelepiped shape and whose top is open; a first unit partition which is disposed inside of the box body and is configured to divide the inner side of the box body into a first unit chamber and a second unit chamber; and a second unit partition which is configured to interconnect the first unit partition and the inner wall of the box body for thereby forming a unit separation space,