A liquid dispensing apparatus that is adapted to eject a liquid in a measuring bore (11, 34, 35) by moving a piston (3, 36, 37) reciprocally, the liquid dispensing apparatus comprising: a liquid contact member that has first and second measuring bores (11, 34, 35); a first piston (3, 36) sliding in the first measuring bore (11, 34) in close contact therewith and a second piston (3, 37) sliding in the second measuring bore (11, 35) in close contact therewith; a supply channel communicating with a storage unit; an ejection channel communicating with a nozzle; a switching valve that is disposed in a space in the liquid contact member, and that has a first position at which the first measuring bore (11, 34) is communicated with the supply channel and the second measuring bore (11, 35) is communicated with the ejection channel, and a second position at which the first measuring bore (11, 34) is communicated with the ejection channel and the second measuring bore (11, 35) is communicated with the supply channel; and a valve driving mechanism that is adapted to operate the switching valve; wherein the liquid dispensing apparatus is adapted to suck the liquid into the first and second measuring bores (11, 34, 35) and eject the liquid in the first and second measuring bores (11, 34, 35), and comprises a piston driving mechanism that is adapted to operate an arm connected to the first and second pistons (3, 36, 37), wherein the first and second measuring bores (11, 34, 35) are arranged to oppose to each other on both sides of the switching valve, and the supply channel and the ejection channel are arranged adjacent to the switching valve, characterized in that the valve driving mechanism and the piston driving mechanism are disposed at rear side of the liquid contact member adjacent to each other in a vertical direction. a liquid contact member that has first and second measuring bores (11, 34, 35); a first piston (3, 36) sliding in the first measuring bore (11, 34) in close contact therewith and a second piston (3, 37) sliding in the second measuring bore (11, 35) in close contact therewith; a supply channel communicating with a storage unit; an ejection channel communicating with a nozzle; a switching valve that is disposed in a space in the liquid contact member, and that has a first position at which the first measuring bore (11, 34) is communicated with the supply channel and the second measuring bore (11, 35) is communicated with the ejection channel, and a second position at which the first measuring bore (11, 34) is communicated with the ejection channel and the second measuring bore (11, 35) is communicated with the supply channel; and a valve driving mechanism that is adapted to operate the switching valve; wherein the liquid dispensing apparatus is adapted to suck the liquid into the first and second measuring bores (11, 34, 35) and eject the liquid in the first and second measuring bores (11, 34, 35), and comprises a piston driving mechanism that is adapted to operate an arm connected to the first and second pistons (3, 36, 37), wherein the first and second measuring bores (11, 34, 35) are arranged to oppose to each other on both sides of the switching valve, and the supply channel and the ejection channel are arranged adjacent to the switching valve, characterized in that the valve driving mechanism and the piston driving mechanism are disposed at rear side of the liquid contact member adjacent to each other in a vertical direction.