The present invention pertains to improving the mixing efficiency in a static mixer for mixing two or more types of liquids. The present invention provides a static mixer 10 comprising: a liquid inlet 12 through which two or more types of liquids flow in; a liquid mixing unit 14 for mixing the two or more types of liquids, the liquid mixing unit 14 being connected to the post stage of the liquid inlet 12; and a liquid outlet 16 through which the mixed liquid flows out, the liquid outlet 16 being connected to the post stage of the liquid mixing unit 14, The liquid mixing unit 14 has a turbulent diffusion mixer unit 20 configured so as to include: a substantially cylindrical, long and thin capillary mixer 22,