A jet flow discharge nozzle includes a tubular partition wall, a tubular casing which covers an outer periphery of the tubular partition wall, and a bifurcation which extends in an axial direction of the tubular partition wall and the casing so as to support downstream ends of the tubular partition wall and the casing from outside. Inside of the tubular partition wall is defined as a flow path for a high-speed core flow. A space between the tubular partition wall and the casing is defined as a flow path for a low-speed bypass flow. A pair of first projections is provided at a downstream edge of the tubular partition wall near the bifurcation at positions symmetric about the bifurcation. One of ridges of each of the first projections faces an upstream side. The invention reduces noise by avoiding adverse effects of the presence of the bifurcation on an increase in noise.