PROBLEM TO BE SOLVED: To provide a very small and inexpensive liquid collector capable of simply and quickly collecting a trace quantity of liquid. SOLUTION: The liquid collector has a suction pump 5 comprising a housing 11, a diaphragm 12 partitioning the housing 11 into a first and second chambers 17 and 18, and a polymer gel 13 stored in the second chamber 18 and deforming the diaphragm 12, reducing the volume of the first chamber 17, and producing volume deformation, restoring the deformation of the diaphragm 12, when a specific stimulus is given, and enlarging the volume of the first chamber 17, causing negative pressure, and a hollow needle 3 continuously connected to the first chamber 17 and collecting a liquid by negative pressure.