An installation for analyzing a chromatography eluate, said installation comprising: - a chromatograph in gaseous phase equipped with an eluate outlet, - a mass spectrometer able to provide, at its output, data representative of the result of the spectrometric analysis of at least a portion of the eluate, - at least one flow divider comprising two fluid inlets (31, 32) and at least fluid two outlets (33, 34, 35), one of said inlets (31, 32) being coupled to a pressurized gas source, the other, called eluate inlet, being coupled to the eluate outlet of the chromatograph, one of the outlets (33, 34, 35) of the flow divider being coupled to the inlet of the mass spectrometer, - at least one fluid switch comprising at least one inlet and two fluid outlets (42, 43) respectively in fluid communication with said fluid inlet by a fluid flow line (44, 45), and a control device for the switch able to allow a selective supply of fluid for said fluid outlet (42, 43) by said fluid inlet, this control device of the switch comprising at least one fluid flow circuit including at least two flow paths (51, 52) connected at their inlet to a pressurized gas source and emerging at their outlet for one, in a line, the other in the other fluid flow line of the switch, said flow paths (51, 52) being selectively closable by closing off means configured, in the closed off state of one of the paths, to leave the fluid flow line associated with that path free in which said line emerges and allow the discharge of fluid by said fluid flow line, characterized in that the fluid inlet of the or at least one of the fluid switches is connected to a fluid outlet (34, 35) of the flow divider separate from the flow outlet of the flow divider coupled to the mass spectrometer. - a chromatograph in gaseous phase equipped with an eluate outlet, - a mass spectrometer able to provide, at its output, data representative of the result of the spectrometric analysis of at least a portion of the eluate, - at least one flow divider comprising two fluid inlets (31, 32) and at least fluid two outlets (33, 34, 35), one of said inlets (31, 32) being coupled to a pressurized gas source, the other, called eluate inlet, being coupled to the eluate outlet of the chromatograph, one of the outlets (33, 34, 35) of the flow divider being coupled to the inlet of the mass spectrometer, - at least one fluid switch comprising at least one inlet and two fluid outlets (42, 43) respectively in fluid communication with said fluid inlet by a fluid flow line (44, 45), and a control device for the switch able to allow a selective supply of fluid for said fluid outlet (42, 43) by said fluid inlet, this control device of the switch comprising at least one fluid flow circuit including at least two flow paths (51, 52) connected at their inlet to a pressurized gas source and emerging at their outlet for one, in a line, the other in the other fluid flow line of the switch, said flow paths (51, 52) being selectively closable by closing off means configured, in the closed off state of one of the paths, to leave the fluid flow line associated with that path free in which said line emerges and allow the discharge of fluid by said fluid flow line, characterized in that the fluid inlet of the or at least one of the fluid switches is connected to a fluid outlet (34, 35) of the flow divider separate from the flow outlet of the flow divider coupled to the mass spectrometer.