PURPOSE: A tundish is provided to measure the internal temperature thereof in real time even in a high-temperature condition because an optic fiber temperature sensor is installed between an outer steel shell and an inner refractory material. CONSTITUTION: A tundish comprises an outer steel shell(10), inner refractory materials(30,31), and an optical fiber temperature sensor installed between the outer steel shell and the inner refractory materials. The optical fiber temperature sensor is inserted in a groove formed on the underside of a metal plate with excellent thermal conductivity.