A cylindrical mixer having an opening portion on both ends forms an axial flow path and a first fluid introduced into the axial flow path through the opening portion at one end flows therethrough in the axial direction and the first fluid exits from the opening portion at the other end; and a spiral flow path and a second fluid introduced into the spiral flow path through a hole formed in a peripheral wall of the mixer is made to flow along an inner peripheral surface of the mixer while being swirled in a spiral manner about an axis of the axial flow path so that the first fluid and the second fluid are mixed and a mixture of the first fluid and the second fluid exits from an opening potion at the end to refine and homogenize a dispersion phase on a micro level to a sub-micro level.