A flow controller including a flow channel resistance disposed in a carrier gas supply flow channel, a control valve, pressure detecting portion 22 and a pressure difference detecting portion, a storage part storing a first calibration curve indicating a correlation between a pressure difference Δp and a total flow volume ftemp1 at the first set supply pressure Pin, ref1 and a second calibration curve indicating a correlation between a pressure difference Δp and the total flow volume ftemp2 at a second set supply pressure Pin,ref2 larger than the first set supply pressure Pin,ref1 is provided. A total flow volume f of the carrier gas is calculated based on the supply pressure pin detected by the pressure detecting portion, pressure difference Δp information detected by the pressure difference detecting portion, the first calibration curve and the second calibration curve.