Automatic analysis device and cleaning mechanism in automatic analysis device

There is a possibility that, due to contact by a cleaning tip for sucking up a cleaning liquid for the next analysis when the inside of a repeatedly used reaction container is cleaned, the inner wall of the reaction container was damaged and thereby an analysis result was affected. The invention provides a device and a cleaning mechanism for a reaction container in the device that are characterized by being provided with: a reaction disk for holding a reaction container; a sample dispensing mechanism for dispensing a sample to the reaction container; a reagent dispensing mechanism for dispensing a reagent to the reaction container; an optical system comprising a light source for applying light to a mixture of the sample and the reagent dispensed to the reaction container, and a detector for detecting the light applied from the light source; and a cleaning mechanism for cleaning the reaction container, wherein the cleaning mechanism is provided with a cleaning liquid supply nozzle for supplying a cleaning liqu