A droplet ejection apparatus has an ejection unit that ejects a droplet of liquid onto a target. The ejection unit is arranged in a multi-joint robot. The robot moves the ejection unit in a two-dimensional direction above the target. The ejection unit includes a droplet ejection head, a liquid tank, and an auto-seal valve. The auto-seal valve adjusts the pressure of the liquid supplied from the liquid tank to the droplet ejection head to a predetermined pressure. The auto-seal valve has a valve body that is movable between a closing position and an opening position in correspondence with the difference between the pressure of the liquid in the droplet ejection head and the pressure of the liquid in the liquid tank. The valve body is arranged such that the direction of acceleration that produces force capable of moving the valve body from the closing position to the opening position differs from the direction of acceleration of the ejection unit moving in the two-dimensional direction.