In an array of coke ovens each including a plurality of combustion chambers having a plurality of flue nozzles, a measuring car equipped with a temperature measuring member runs above the array in a direction of the array or in a longitudinal direction of the combustion chambers so as to detect thermal radiations passing through the flue nozzles to measure combustion chamber temperature. The measured temperature is sent to a remote control room through antennae. Where a coal charging car of a Rahmen construction is used an antenna is also provided for the coal charging car so that even when the measuring car runs beneath the coal charging car, radio communication can be assured. The temperature of the combustion chambers can be readily and accurately measured by linearly running the measuring car whether combustion is effected in one or the other side of the combustion chambers.