A gas chromatograph having a column which separates respective components contained in a gas sample introduced via a carrier gas over time, wherein an analysis mode and a standby mode can be switched and executed. The gas chromatograph apparatus comprises: a carrier gas flow path, a column protection gas flow path, a flow path switching part provided between the carrier gas flow path and the column protection gas flow path and a column so that only one of the carrier gas or a column protection gas is introduced into the column, and a flow path control part for controlling the flow switching part so as to introduce the carrier gas into the column at the time of the analysis mode and introduce the column protection gas into the column at the time of the standby mode.