<p>Disclosed is a process for producing chlorine by oxidizing hydrogen chloride in a fluidized-bed reactor including a catalyst layer. Any horizontal cross-section (A) of the part of the fluidized-bed reactor in which the catalyst layer is present has an inner diameter in the range of 0.2 to 10.0 m, and the cross-section (A) has an equivalent diameter in the range of 0.1-5.0 m. By using the process, activity in the reaction and catalyst flowability can be maintained over a long period, and it is possible to continuously and efficiently produce chlorine.</p>
