Detector for chromatograph

A detector for a chromatograph includes a light source, and a light detector that detects light generated based on turning on of the light source, wherein the light source includes a deuterium lamp, and a deuterium lamp power supply circuit connected to the deuterium lamp, and the deuterium lamp power supply circuit includes a DC voltage generation circuit that generates a DC voltage by performing a switching operation, a rectifying operation and a smoothing operation, a voltage application circuit that applies a DC voltage generated by the DC voltage generation circuit to the deuterium lamp, a first feedback circuit that feeds a first feedback voltage changing depending on a DC voltage to the DC voltage generation circuit such that the DC voltage generated by the DC voltage generation circuit becomes close to a discharge maintaining voltage, after electric discharge of the deuterium lamp is started, and a constant current control circuit that controls a discharge current of the deuterium lamp to be constant.