Provided is a flux that is able to suppress any solder bridges even when it is applied to the narrow pitched electrodes such that the bridge occurs when using the past flux. The flux is characterized by containing 15% by mass or more and 35% by mass or less of polyoxyalkylene ethylenediamine, 2% by mass or more and 15% by mass or less of an organic acid, 10% by mass or more and 30% by mass or less of a base material, 3% by mass or more and 30% by mass or less of an amine and 20% by mass or more and 40% by mass or less of a solvent.