To provide a temperature measurement apparatus capable of always accurately measuring in-furnace temperature without reducing a heat insulating effect by the influence of the in-furnace temperature as to the temperature measurement apparatus which measures in-furnace temperature in each treatment chamber while preventing the influence of a liquid in an oil tank on a continuous carburizing furnace provided with a hardening chamber for immersing a work in the oil tank.

A temperature measurement apparatus 1 includes: a measurement apparatus body 2 for processing measurement data; an inner heat-resistant case 31 for placing the measurement apparatus body 2 in its inside; a heat insulating layer 4 for packaging the inner heat-resistant case 31 through a heat accumulating material 32; and an outer heat-resistant case 6 for placing the heat insulating layer 4 in its inside. In the temperature measurement apparatus 1, the heat insulating layer 4 is composed of mutually laminated outside heat insulating materials 4A and inside heat insulating materials 4B and arranged so as to be slid in the lamination direction along the inner surface of the outer heat-resistant case 6, and energization means 5, 5 for energizing the heat insulating layer 4 in a direction for holding the heat insulating layer 4 in the lamination direction are arranged between the outer heat-resistant case 6 and the heat insulating layer 4.