PURPOSE: To prevent the occurrence of a thermal shock to a heating furnace itself and to provide a high sample cooling speed by a method wherein a cooling gas outbound passage communicated with the cooling gas inlet port of a header and a cooling gas inbound passage communicated with a cooling gas outlet port are formed in a sample cartridge.

CONSTITUTION: A cartridge with a rapid cooling mechanism comprises a hollow cylindrical sample cartridge 1 having a sample containing chamber 2, a cooling gas input port 5, and a cooling gas outlet port 6. The sample cartridge 1 is provided at one end with a header 3 and at the other end with a seal cap 7, and the sample cartridge l is provided with a cooling gas outbound passage 19 communicated with the inlet port 5 and a cooling gas inbound passage 20 communicated with the outlet port 6. As a result, a sample in the sample cartridge 1 is heated by a heating furnace togetherwith the cartridge 1 and simultaneously with completion of heating, cooling gas is forced to flow through the inlet port 5 to the outbound passage 19 and discharged through the outlet port 6 through the inbound passage 20. This constitution cools a sample in such a way that the heating furnace is not sealed with cooling gas but forced to flow in the sample cartridge 1.