A local exhaust device includes a main body part having an inlet port formed on a lower surface thereof and a vertex forming device installed on the main body part for forming a vortex so as to induce intake of external air through the inlet port. The vortex forming device comprises a swirler disposed on the inlet port and rotated so as to form a vortex; a driving part for rotating the swirler, and a flow guide disposed on the inlet port for guiding downstream the flowing air in a rotating process of the swirler. The flow guide comprises an upper surface disposed on an upper portion of the swirler, wherein the upper surface of the flow guide comprises an open region for opening the upper portion of the swirler and a closed region for blocking the upper portion of the swirler.