An automated analyzer includes an analysis operation part that causes a sample and a reagent to react and based on the reaction result performs analysis of the sample, wherein: the automated analyzer includes a plurality of units constituting the analysis operation part, a temperature adjustment mechanism that heats or cools the units, a temperature sensor that measures the temperature of the units, and a control part that controls the temperature adjustment mechanism. The control part sets the measurement startable temperature range of each unit, which is the temperature range of the operation specification thereof, and the operable temperature range, which is a temperature range that is wider than the measurement startable temperature range, and starts the analysis process of the sample when the temperature of each unit has entered the operable temperature range.