To stably manufacture chlorine for a long time by using an obtained support ruthenium oxide as a catalyst to oxidize hydrogen chloride with oxygen.

The method for manufacturing a support ruthenium oxide is such that allows a ruthenium compound to be supported on a titania carrier where silica is supported on a titania and sinters the same under the atmosphere of an oxidizing gas. The titania carrier can be prepared by allowing a silica compound to be supported on the titania and burning the same under the atmosphere of the oxidizing gas.