PURPOSE: To prevent the quality of products from being degraded, and protect facility and equipment from being damaged by installing a signal correction section which corrects the output of a control section based on a correction factor obtained from a correction factor arithmetic section and controls the temperature of a furnace side.

CONSTITUTION: This temperature control device controls a furnace 1 so as to keep steady operation state based on control variables obtained by measuring the temperature of the furnace 1 by a control section 6 and a target value set by an operation target value set point station setter 3 or a temporary suspension target value set point station setter 4. It is also a control device designed to suspend the operation temporarily. If the operation of the furnace 1 is suspended temporarily, a correction factor is obtained based on control variables obtained by the measurement of a target set value and a furnace temperature conducted by a correction factor arithmetic operation section 11. When the temporarily suspended state is canceled, then routine operation starts, an operation signal output from the control section 6 is corrected for a specified time based on a correction factor obtained during temporary suspension by a signal correction section 18, which prevents the temperature of the furnace from rising abnormally.