In a device for transporting liquid, liquid to be transported is enclosed by an oil droplet, which is fractionated with air, for manipulation. Moreover, as a method for supplying liquids wherein a plurality of liquids are enclosed by an oil droplet sequentially and treated, liquid enclosed by an oil droplet is formed by associating one oil with one liquid in a liquid introducing section. According to the present invention, even in the case where a plurality of liquids are manipulated, it is possible to manipulate stably without affecting other liquids. Moreover, it is possible to treat as a liquid enclosed by an oil droplet successively in the device for transporting liquid, thereby allowing the invention to be applied to a system for analyzing easily.