Abstract: An air nozzle for producing a sheath-core type fancy yarn, comprising a hollow cylindrical nozzle body in which a vortex occurs around an axis thereof due to a suction flow of a subatmospheric pressure source. Within the nozzle body a conical cap and a ring body are arranged in series. A sheath yarn is overfed into the nozzle body in the tangential direction to the inner surface of the body and wraps around the conical cap to form a plurality of loops due to the vortex, then entangles a core yarn running straight through the nozzle body. Since an outer surface of the conical cap and a central opening of the ring body guide the vortex smoothly along a yarn path, a fancy yarn having uniformly and tightly entangled loops can be obtained.