An automated analyzer provided with an analysis operation part that causes a sample and a reagent to react and on the basis of the reaction result performs analysis of the sample, the automated analyzer comprising: a plurality of units constituting the analysis operation part, said units including a rack conveying line, a reagent cooling unit, an incubator disk, a sample dispensing mechanism, a reagent dispensing mechanism, a detector unit that performs analysis of a reaction solution, and a conveyance mechanism; characterized in that a subset of the plurality of units which consists of the reagent cooling unit, the incubator disc and the detector unit is provided with a plurality of temperature adjustment mechanisms that heat or cool the plurality of units individually; a plurality of temperature sensors each measuring a temperature of one of the units; a control part that controls the plurality of temperature adjustment mechanisms individually, wherein the control part sets: - a measurement startable temperature range of each unit, which is the temperature range of the operation specification thereof, and - an operable temperature range, which is a temperature range that is wider than the measurement startable temperature range and includes the measurement startable temperature range, and a storage device for storing the measurement startable range and the operable temperature range associated with the respective units; wherein the control part is configured to start, when there is an analysis request from the user, a pre-analysis preparatory operation of the sample when the temperatures of all of the units included in a subset of the plurality of units have entered the operable temperature range of the unit, while continuing to control the plurality of temperature adjustment mechanisms such that temperature of each unit in the subset of the units reaches the measurement startable temperature range, wherein said pre-analysis preparatory operation includes: - an operation check of the sample dispensing mechanism, the reagent dispensing mechanism and the detector unit. a plurality of units constituting the analysis operation part, said units including a rack conveying line, a reagent cooling unit, an incubator disk, a sample dispensing mechanism, a reagent dispensing mechanism, a detector unit that performs analysis of a reaction solution, and a conveyance mechanism; characterized in that a subset of the plurality of units which consists of the reagent cooling unit, the incubator disc and the detector unit is provided with a plurality of temperature adjustment mechanisms that heat or cool the plurality of units individually; a plurality of temperature sensors each measuring a temperature of one of the units; a control part that controls the plurality of temperature adjustment mechanisms individually, - a measurement startable temperature range of each unit, which is the temperature range of the operation specification thereof, and - an operable temperature range, which is a temperature range that is wider than the measurement startable temperature range and includes the measurement startable temperature range, and - an operation check of the sample dispensing mechanism, the reagent dispensing mechanism and the detector unit.