Chlorine is produced by reacting hydrogen chloride and oxygen in the presence of a catalyst composed of a chromium oxide as a principal component. The reaction is carried out in a fluidized bed reactor (1) equipped at vertical intervals not greater than 100cm with a plurality of perforated horizontal plates (3) having a perforation rate of 10-60% in a reaction zone in which the catalyst is fluidized in operation. The reaction zone (2) is above a gas diffuser plate.
