A mixer for mixing two materials includes a casing and a mixing component. The mixing component has a first vertical wall, a second vertical wall in parallel to the first vertical wall, an inlet baffle, an outlet baffle, a plurality of first arc shape guiding plates and a plurality of second arc shape guiding plates. The inlet baffle and the outlet baffle are disposed on the two ends of the first and second vertical walls, respectively. The first arc shape guiding plates and second arc shape guiding plates are disposed between the inlet and outlet baffles, and the first and second arc shape guiding plates are mutually spaced and disposed in opposite to each other. The two materials are imported from the inlet baffle and guided to flow through the first and second arc shape guiding plates, and subsequently mixed and exported from the outlet baffle.