In an analysis system for detecting amounts of components contained in samples, many samples can be measured simultaneously in the whole of the system by use of compact inexpensive photometers. An LED with low heat generation and a long life span is used as a light source. Compactness is achieved by bended optical axis instead of a straight one. Components for bending an optical axis and components for condensing light to ensure an amount of light are in common use to reduce the number of components. Compactness, reduction of the number of components, and integration achieve easy optical axis alignment and precise measurement.