To appropriately fill a functional liquid into flow channels and to reduce functional fluid quantity going to waste in filling the functional liquid in an assembly to fill the functional liquid into the flow channels inside respective functional fluid droplets ejecting heads by joining a plurality of caps connected from a plurality of suction flow channels to a sucking means via a converge channel for suction to a plurality of the functional fluid droplets ejecting heads connected to a functional fluid supplying means via a supply line channel respectively.

The method is characterized by being provided with a step to suck the functional liquid from the functional fluid supplying means 204 by operating the sucking means 141 and the respective functional fluid droplets ejecting heads 51 for suction via a plurality of the caps 113 and a step to close the suction flow channels 174 connected to the caps 113 in the order of reaching of the functional fluid to each of the cap 113 via the functional fluid droplets ejecting head 51 resulting from the step to suck the functional fluid.