Liquid chromatograph device

A liquid chromatograph device comprising:

• a thermostatic chamber;
• one or a plurality of outer doors that are disposed at the front surface of said thermostatic chamber;
• a heat block that is disposed in said thermostatic chamber for heating a separation column;
• a heating means for heating said heat block;
• a temperature detection means for detecting the temperature of said heat block;
• a flowing means for flowing air between the inside and outside of said thermostatic chamber;
• a control means for controlling the supply of power to said heating means based on the detection result of said temperature detection means;
• and
• an inner door between said outer door and said heat block, said inner door comprising a hollow inner door main body, a heat-insulating material that is housed within said inner door main body so as to form an air chamber at least between the heat-insulating material and the surface on the outer door side of said inner door main body, and outlet slits and inlet slits that are formed in said inner door main body;
• wherein said flowing means causes air to flow from the outer door side through said inlet slit into said air chamber and air inside said air chamber to flow through said outlet slit to the heat block side.