A discharge method includes discharging discharge products including a first discharge gas and solid by-products from a process chamber, in which a substrate processing process is performed in a vacuum state, into an inside of a collection device, collecting the solid by-products in the collection device, introducing a portion of a second discharge gas discharged from a load lock chamber into the collection device, and vaporizing the solid by-products in the collection device and discharging vaporized solid by-products to an outside of the collection device.

A discharge method includes discharging discharge products including a first discharge gas and solid by-products from a process chamber, in which a substrate processing process is performed in a vacuum state, into an inside of a collection device, collecting the solid by-products in the collection device, introducing a portion of a second discharge gas discharged from a load lock chamber into the collection device, and vaporizing the solid by-products in the collection device and discharging vaporized solid by-products to an outside of the collection device.