An automatic analyzer comprising: an analysis unit adapted to perform an analysis process for analyzing a specimen to be analyzed; a storage unit adapted to store a result of the analysis process, to cumulatively store information on occurrence of events of registration, change and deletion of analysis parameters which are preset analysis conditions in the analysis process, and to cumulatively store information on occurrence of events of registration, deletion and replacement of reagent information which is information on a reagent used for analysis of the specimen, for each analysis item of the specimen; a display unit adapted to display the analysis result of the specimen and information on occurrence status of the events; and a control unit adapted to control an operation of the analysis process of the specimen by the analysis unit, wherein the control unit is adapted to read the information on the events of registration, change and deletion of the analysis parameters and the information on the events of registration, deletion and replacement of the reagent information from the storage unit and to display the read information on the display unit in chronological order, wherein the control unit is adapted to place the information on the events of registration, change or deletion of the analysis parameters, and the information on the events of registration, deletion or replacement of the reagent information, on a plane in which an axis relating to an occurrence time of the event and an axis relating to an occurrence order of the events are set to be orthogonal to each other, on the display unit, and wherein the control unit is adapted to determine, for each event, whether or not there is a relation with the already displayed events, and to connect each event by a line with all related events in chronological order when such a relation exists. an analysis unit adapted to perform an analysis process for analyzing a specimen to be analyzed; a storage unit adapted to store a result of the analysis process, to cumulatively store information on occurrence of events of registration, change and deletion of analysis parameters which are preset analysis conditions in the analysis process, and to cumulatively store information on occurrence of events of registration, deletion and replacement of reagent information which is information on a reagent used for analysis of the specimen, for each analysis item of the specimen; a display unit adapted to display the analysis result of the specimen and information on occurrence status of the events; and a control unit adapted to control an operation of the analysis process of the specimen by the analysis unit, wherein the control unit is adapted to read the information on the events of registration, change and deletion of the analysis parameters and the information on the events of registration, deletion and replacement of the reagent information from the storage unit and to display the read information on the display unit in chronological order, wherein the control unit is adapted to place the information on the events of registration, change or deletion of the analysis parameters, and the information on the events of registration, deletion or replacement of the reagent information, on a plane in which an axis relating to an occurrence time of the event and an axis relating to an occurrence order of the events are set to be orthogonal to each other, on the display unit, and wherein the control unit is adapted to determine, for each event, whether or not there is a relation with the already displayed events, and to connect each event by a line with all related events in chronological order when such a relation exists.