Gas chromatograph device

This gas chromatograph is provided with a column module in which the temperature of a separation column can be independently adjusted. The column module is held in an oven such that the separation column is in a horizontal state. The column module is provided with: the separation column in which a sample gas is separated into each of the components thereof; a column accommodation member in which the periphery of the separation column is surrounded by an adiabatic member and accommodated, said column accommodation member being provided with a gap between the separation column and the adiabatic member so as to allow air to flow along the separation column; and a heater which is provided inside the column accommodation member, which is in direct or indirect contact with the separation column, and which heats the separation column. The column accommodation member is provided with: an air inlet for drawing external air into the gap between the separation column and the adiabatic member; and an exhaust port for expelling air in the gap.