To provide an inexpensive liquid extraction device which automatically detects the residual quantity of liquid in a liquid vessel with a simple structure and also accurately obtains the detection precision.

A storage part 34 is provided where a flexible liquid vessel 3 where a liquid is stored, is stored in the state inclined downward toward an extraction port part 52 formed in one end of the liquid vessel 3. A quantitative extraction means 4 on which the extraction port part 52 of the liquid vessel 3 stored in a storage part 34 is mounted and which extracts a fixed quantity of the liquid in the liquid vessel 3 through the extraction hole part 52 is provided at a lower position from the storage part 34. An operation switch 121 operation by a part where the volume of the liquid vessel 3 is expanded by the liquid led toward the extraction hole part 52 in the liquid vessel 3 is arranged above the quantitative extraction means 4 corresponding to the vicinity of the extraction port part 52 of the liquid vessel 3. The residual quantity of the liquid in the liquid vessel 3 is detected by the operation state of the operation switch 121.