The present invention provides an automatic analyzer capable of reducing the time necessary for analysis processing by making various operations pertaining to the analysis processing more efficient. More specifically, the present invention is characterized in that, from among a plurality of ending operation items set as analysis ending operations to perform at the end of analysis operations for analyzing a sample under analysis, one or more ending operation items to be performed are selected, and on the basis of monitoring results of monitoring the status of an automatic analyzer during the period from the end of the analysis ending operations to the start of analysis preparation operations for preparing for the analysis operations, one or more preparation operation items to be performed are selected from among a plurality of preparation operation items set as analysis preparation operations.