The present invention provides a thermal analyzer having a cooling device which can realize cooling of a specimen to a temperature equal to or below −100° C. by suppressing the consumption of gas also in performing rapid cooling. The cooling device includes a cooling gas inlet port and a cooling gas discharge port for a gas cooling device and an electric cooling device fixing mechanism, wherein the cooling device and the thermal analyzer are brought into thermal contact with each other. Due to such a constitution, it is possible to simultaneously connect the gas cooling device and the electric cooling device.