To positively judge the state of lamp burnout by distinguishing the reduction of detection quantity of light to a photo detector, for example, due to the inclusion of muddy water from that due to the lamp burnout in a colorimetry analysis device.

Based on the absorbance of a sample that is obtained by transmitting light 3 from a light source 2 to a sample measurement cell 1 with a transmission window and by detecting the transmission light by a photo detector 4, the turbidity or chromaticity of the sample is measured by a colorimetry analysis device. The device has a judgment circuit 13 that judges the lamp burnout of the light source 2 based on a photo detector 12 for monitoring the quantity of light of the light source 2 and a signal from the photo detector 12 for monitoring.