We report the utilization of giant unilamellar vesicles (GUVs) as a platform of handling chemical and biochemical reagents in femtoliter volumes. GUVs with diameter 5 to 10 μm containing chemical reagents together with inert polymers were subjected to electric pulses for fusion (electrofusion). After mixing of reagents, the fused GUV spontaneously deformed to a budding shape, separating the mixed solution into multiple sub-volumes^<(1)>. Here we utilized the microfluidic channel and the optical tweezers to select GUVs in interest, make them in contact, and fuse them together for mixing and dispensing chemical reagents. We also show that, by lowering the ambient temperature close to the phase transition temperature T_m of the lipid used, daughter GUVs completely detached (fission). This process completes all features for liquid handing used in biochemistry at femtoliter volumes, which have been unattained with the previous technologies.