An automated analyzer for performing a first processing operation to create a pretreated specimen by pretreating a specimen with a pretreatment solution in first reaction cells and a second processing operation to create a reacted specimen by reacting the pretreated specimen with a reagent in second reaction cells, said automated analyzer comprising: a turntable on which the first and second reaction cells are arranged annularly; control means for controlling rotation of the turntable; first aliquot dispensing means for selectively pouring out the pretreatment solution and the reagent in a first position; second aliquot dispensing means for selectively performing dispensing of aliquots of the specimen and injection of aliquots of the pretreated specimen in a second position; stirring means for selectively performing stirring of the pretreatment solution and the specimen and stirring of the pretreated specimen and the reagent in a third position; and measuring means for measuring the reacted specimen; characterised in that said control means repeatedly performs a first control operation for rotating the turntable through a first angle in a first direction and then bringing the turntable to a halt and a second control operation for rotating the turntable through a second angle in a second direction opposite to the first direction and then bringing the turntable to a halt; wherein said second reaction cells are spaced by the second angle in the first direction from the first reaction cells; wherein the turntable is so rotated that the first and second reaction cells are halted at least in the first, second, and third positions by repetitive execution of the first control operation and the second control operation; wherein said second aliquot dispensing means sucks the pretreated specimen when the first reaction cell containing the pretreated specimen is halted in the second position and pours out the sucked pretreated specimen when the second reaction cell is halted in the second position; and wherein said second angle is smaller than said first angle. a turntable on which the first and second reaction cells are arranged annularly; control means for controlling rotation of the turntable; first aliquot dispensing means for selectively pouring out the pretreatment solution and the reagent in a first position; second aliquot dispensing means for selectively performing dispensing of aliquots of the specimen and injection of aliquots of the pretreated specimen in a second position; stirring means for selectively performing stirring of the pretreatment solution and the specimen and stirring of the pretreated specimen and the reagent in a third position; and measuring means for measuring the reacted specimen; characterised in that said control means repeatedly performs a first control operation for rotating the turntable through a first angle in a first direction and then bringing the turntable to a halt and a second control operation for rotating the turntable through a second angle in a second direction opposite to the first direction and then bringing the turntable to a halt; wherein said second reaction cells are spaced by the second angle in the first direction from the first reaction cells; wherein the turntable is so rotated that the first and second reaction cells are halted at least in the first, second, and third positions by repetitive execution of the first control operation and the second control operation; wherein said second aliquot dispensing means sucks the pretreated specimen when the first reaction cell containing the pretreated specimen is halted in the second position and pours out the sucked pretreated specimen when the second reaction cell is halted in the second position; and wherein said second angle is smaller than said first angle.