A process for producing chlorine comprising the step of oxidizing hydrogen chloride in a gas containing hydrogen chloride with a gas containing oxygen in a fixed bed reaction system having a reaction zone comprising a catalyst-packed layer, wherein a superficial linear velocity of the gas in a column is from 0.70 to 10 m/sec. According to this process, the stable activity of the catalyst is maintained and chlorine can be stably obtained at a high yield since the excessive hot spot in the catalyst-packed layer is suppressed and the catalyst-packed layer can be effectively used.