A blood coagulation analyzer comprising: a light irradiation unit configured to apply light onto a container configured to store a measurement specimen containing a sample and a reagent, and comprising: light sources including a first light source configured to generate light of a first wavelength for blood coagulation time measurement, a second light source configured to generate light of a second wavelength for synthetic substrate measurement, and a third light source configured to generate light of a third wavelength for immunonephelometry measurement; a light reception part configured to receive light transmitted through the container; an analysis unit configured to analyze the sample using an electric signal outputted from the light reception part; characterised in that: the light irradiation unit comprises: input optical fiber parts (30, 330) facing the respective light sources, wherein each of the input optical fiber parts comprises optical fibers and an incident end (31, 331); and output optical fiber parts, wherein each of the output optical fiber parts comprises optical fibers and an exit end; and in that: the blood coagulation analyzer further comprises: light source holders holding the respective light sources; incident end holders holding incident ends (31, 331) of the input optical fiber parts such that the incident ends face the respective light sources; and detection units, each of the detection units including container installation sections for installing containers, each storing a sample, and light reception parts provided corresponding to the container installation sections, wherein the output optical fiber parts correspond to the respective detection units whereby the optical fibers associated with the different light sources are mixed and distributed approximately evenly at the exit ends of the output optical fiber parts. a light irradiation unit configured to apply light onto a container configured to store a measurement specimen containing a sample and a reagent, and comprising: light sources including a first light source configured to generate light of a first wavelength for blood coagulation time measurement, a second light source configured to generate light of a second wavelength for synthetic substrate measurement, and a third light source configured to generate light of a third wavelength for immunonephelometry measurement; a light reception part configured to receive light transmitted through the container; an analysis unit configured to analyze the sample using an electric signal outputted from the light reception part; characterised in that: the light irradiation unit comprises: input optical fiber parts (30, 330) facing the respective light sources, wherein each of the input optical fiber parts comprises optical fibers and an incident end (31, 331); and output optical fiber parts, wherein each of the output optical fiber parts comprises optical fibers and an exit end; and in that: the blood coagulation analyzer further comprises: light source holders holding the respective light sources; incident end holders holding incident ends (31, 331) of the input optical fiber parts such that the incident ends face the respective light sources; and detection units, each of the detection units including container installation sections for installing containers, each storing a sample, and light reception parts provided corresponding to the container installation sections, wherein the output optical fiber parts correspond to the respective detection units whereby the optical fibers associated with the different light sources are mixed and distributed approximately evenly at the exit ends of the output optical fiber parts. light source holders holding the respective light sources; incident end holders holding incident ends (31, 331) of the input optical fiber parts such that the incident ends face the respective light sources; and detection units, each of the detection units including container installation sections for installing containers, each storing a sample, and light reception parts provided corresponding to the container installation sections, incident end holders holding incident ends (31, 331) of the input optical fiber parts such that the incident ends face the respective light sources; and detection units, each of the detection units including container installation sections for installing containers, each storing a sample, and light reception parts provided corresponding to the container installation sections, wherein the output optical fiber parts correspond to the respective detection units whereby the optical fibers associated with the different light sources are mixed and distributed approximately evenly at the exit ends of the output optical fiber parts.