Provided is a chlorine evolution method which includes contacting an anode with chloride based aqueous solution and generating chlorine as a main reaction at the anode, in which a main reaction of the anode is chlorine evolution, and the chlorine evolution anode which is low in potential of the anode for chlorine evolution, thereby being able to decrease an electrolytic voltage and lower an electric energy consumption rate. The chlorine evolution anode of the present invention is a chlorine evolution anode in which chlorine evolution from an aqueous solution is a main reaction of the anode and also in which a catalytic layer containing amorphous ruthenium oxide and amorphous tantalum oxide is formed on a conductive substrate.