An automatic analyzer comprising: a nozzle that is adapted to dispense any one liquid of a sample and a reagent to a reaction container ; a dispensing mechanism (7-10) that includes an arm supporting the nozzle by an elastic member ; a controller that is adapted to control vertical movement and horizontal movement of the arm and analyze a mixed liquid of a sample and a reagent dispensed into the reaction container ; and a contact determination unit that is adapted to determine that the nozzle is in contact with an object, wherein the nozzle includes a stop position detection plate , the arm includes a stop position detector detecting the stop position detection plate , and the controller includes a memory capable of storing a moving distance of the arm , the contact determination unit is adapted to determine the moving distance to be stored in the memory on the basis of a distance between a boundary position where the stop position detector detects the stop position detection plate and a boundary position where the contact determination unit determines a contact between the nozzle and the object; the automatic analyzer being characterized in that the controller is adapted to stop moving the arm when the stop position detector detects the stop position detection plate during downward movement of the arm , move the arm upwards by an arm moving distance until the stop position detection plate separates from a detection range of the stop position detector and then by the moving distance stored in the memory in advance and then stop the arm with a position where the nozzle is at an elastic contact starting point with a bottom surface of the reaction container , and perform control such that the liquid is discharged in a state where the arm is stopped. a nozzle that is adapted to dispense any one liquid of a sample and a reagent to a reaction container ; a dispensing mechanism (7-10) that includes an arm supporting the nozzle by an elastic member ; a controller that is adapted to control vertical movement and horizontal movement of the arm and analyze a mixed liquid of a sample and a reagent dispensed into the reaction container ; and a contact determination unit that is adapted to determine that the nozzle is in contact with an object, wherein the nozzle includes a stop position detection plate , the arm includes a stop position detector detecting the stop position detection plate , and the controller includes a memory capable of storing a moving distance of the arm , the contact determination unit is adapted to determine the moving distance to be stored in the memory on the basis of a distance between a boundary position where the stop position detector detects the stop position detection plate and a boundary position where the contact determination unit determines a contact between the nozzle and the object; the automatic analyzer being characterized in that the controller is adapted to stop moving the arm when the stop position detector detects the stop position detection plate during downward movement of the arm , move the arm upwards by an arm moving distance until the stop position detection plate separates from a detection range of the stop position detector and then by the moving distance stored in the memory in advance and then stop the arm with a position where the nozzle is at an elastic contact starting point with a bottom surface of the reaction container , and perform control such that the liquid is discharged in a state where the arm is stopped. <EOS>