Method for producing an emulsion comprising droplets (1) in an external solution (2), the droplets containing a fluid (3). The fluid is circulated along a first main pipe (11), some of the fluid circulating in the first main pipe is bled off by a plurality of micro pipes (13) arranged in parallel between the first main pipe and a second main pipe (12) filled with external solution, the droplets are formed by hydrodynamic focusing as the fluid passes from each micro pipe into the second main pipe.