A fixed quantity discharge device for a liquid container is provided. The device includes a container main body in which contents are accommodated, a pipette part including a pipette tube to suction and discharge the contents accommodated in the container main body, and a support disposed in an upper portion of the container main body and including a coupling part formed in an upper end portion thereof to be coupled to the pipette part, a tube accommodation part extending from the coupling part to an interior of the container main body such that the pipette tube is inserted into or withdrawn from the tube accommodation part, and a contents inflow hole formed in a lower end portion thereof to communicate with the interior of the container main body, wherein, when the pipette part is separated from the support, the contents accommodated in the container main body may be suctioned into the pipette tube.