To suppress the influence of heat from an interface part on temperature control of a separation column and also to suppress the influence of room temperature fluctuation outside a main body. A gas chromatograph (1) includes a main body (2) having internal space, a column cartridge (4) disposed in the internal space of the main body (2) and including a case (20), a heater (18) and a separation column (16) for separating components in sample gas, the separation column being accommodated in the case (20) together with the heater (18), and the case (20) being provided with an intake port (26) through which air for cooling the separation column (16) is taken into the case (20), a sample gas supplier (6) for supplying a sample gas to the separation column (16), the sample gas supplier (6) being attached to the main body (2), and being fluidly connected to an inlet of the separation column (16), a detector (8) for detecting components separated in the separation column (16), the detector (8) being attached to the main body (2) and being fluidly connected to an outlet of the separation column (16), an interface part (10) adjusting a temperature of pipes (22; 24) connected to the inlet and the outlet of the separation column (16) in the internal space of the main body (2), a first fan (12) for supplying outside air of the main body (2) into the case (20) of the column cartridge (4) via the intake port (26), and a second fan (14) which is different from the first fan (12), and is for cooling an outer surface of the case (20) of the column cartridge (4) by blowing outside air if the main body (2) to an outer surface of the case (20) of the column cartridge (4).