A semiconductor manufacturing apparatus includes a transfer mechanism including a moving part for holding a substrate to be processed and moving along a longitudinal transferring passage and a plurality of processing units for performing respective processes on the substrate. The processing units are disposed along the transferring passage and the substrate is transferred between the processing units and the transfer mechanism. An exhaust chamber is provided under the processing units, the exhaust chamber having a gas exhaust opening at the side of the transferring passage, the exhaust chamber. Further, a suction exhaust line is connected to the exhaust chamber, and a guide member is provided inside the exhaust chamber or at a position facing the opening, wherein the guide member extends along the transferring passage.