To provide a carriage transfer method capable of maintaining the quality of a carriage throughout a transfer process from a manufacturer to a delivery destination.

A carriage manufacturing room 11 in which the carriage CA is manufactured and a color filter manufacturing room 14 in which a liquid droplet injector IJ for assembling the carriage CA is installed are controlled in temperature each to remain at a predetermined temperature. A transfer case 12 accommodating the carriage CA is provided with a temperature regulator part to control the temperature inside the transfer case 12 to the predetermined temperature. Through cooperation between a preservation solution evaporator and a liquefying recovery device disposed in the transfer case 12, a preservation solution for liquid droplet injection heads is used to form an atmosphere at a predetermined concentration with the preservation solution as an evaporation component.