An exhaust system connected to an exhaust port of a substrate processing apparatus includes: a first exhaust trap having an exhaust input at an upper portion thereof and an exhaust output at a lower portion thereof and cooling a product produced in the substrate processing apparatus; a second exhaust trap installed at a downstream side of an exhaust flow with respect to the first exhaust trap, having an exhaust input at a lower portion thereof and an exhaust output at an upper portion thereof, and cooling the product; a storage unit installed between the first and second exhaust traps and storing the product cooled by the first and second exhaust traps; a first pipe connecting the exhaust port of the substrate processing apparatus and the first exhaust trap; and a second pipe connecting the first exhaust trap, the second exhaust trap and the storage unit.