This text deals with the design, construction and characterization of a subsonic wind tunnel. Chapter 1 shows the state of the art of wind tunnels from their origin to the present, considering those used in research and student applications. Chapter 2 shows the design methodology of a subsonic wind tunnel for flow analysis applications with smoke visualization technique. Finally, chapter 3 presents the wind tunnel construction process and the results of the characterization of the test area as well as the first images obtained of the smoke flow inside porous models.