To provide a temperature control method for a converter exhaust gas cooling device for suppressing a sudden temperature change until reaching a stable control region by preventing the spray quantity of cooling water from being excessive/insufficient by hunting of a cooling water flow regulating valve in the initial stage of combustion gas injection into a converter.

In this temperature control method for the converter exhaust gas cooling device, the set value of cooling water spray quantity is determined by feedback control according to the outlet side exhaust gas temperature of the converter exhaust gas cooling device for cooling converter exhaust gas by spraying cooling water, and the cooling water spray quantity is regulated by PID control to be the set value of cooling water spray quantity. In this case, a fuel injection quantity into the converter at the start of cooling water spray control is suppressed to a predetermined quantity or less. The fuel injection quantity into the converter at the start of cooling water spray control is set to a fuel injection quantity which causes neither excess nor shortage of the cooling water spray quantity by a transient response of cooling water spray quantity control to suppress the fuel injection quantity into the converter at the start of cooling water spray control to the predetermined quantity, and the limit of fuel injection quantity is released after reaching a stable region where an actual value of cooling water spray quantity is equal to the set value of cooling water spray quantity from a control device.