An automatic analyzer , comprising: a dispensing nozzle that sucks a sample from a sample container holding the sample and discharges the sample to a reaction container ; a syringe pump that controls an amount of change in a volume of a fluid; a first pipe that connects the dispensing nozzle and the syringe pump ; a first electromagnetic valve that flows or stops the fluid; a second pipe that connects the first electromagnetic valve and the syringe pump ; a third pipe that includes a heat exchange unit performing heat exchange of the fluid; a case that accommodates at least the syringe pump , the first pipe , the first electromagnetic valve , the second pipe , and the third pipe ; and a heat exchange unit accommodating part that accommodates the heat exchange unit , characterized in that the case further accommodates a branch pipe that branches the fluid, and the third pipe connects the first electromagnetic valve and the branch pipe , the heat exchange unit is formed to be a turning part obtained by extending the third pipe and winding the extended third pipe for a plurality of times so that a length of the third pipe is longer than a sum of a length of the first pipe and a length of the second pipe and the third pipe has a shape of increased surface area, such that the efficiency of heat exchange with ambient air is high and the heat exchange unit has heat exchanging capacity of eliminating a difference between a temperature of ambient air inside the case and a temperature of the fluid in the heat exchange unit , and the heat exchange unit accommodating part is provided on an upper side in the case . a dispensing nozzle that sucks a sample from a sample container holding the sample and discharges the sample to a reaction container ; a syringe pump that controls an amount of change in a volume of a fluid; a first pipe that connects the dispensing nozzle and the syringe pump ; a first electromagnetic valve that flows or stops the fluid; a second pipe that connects the first electromagnetic valve and the syringe pump ; a third pipe that includes a heat exchange unit performing heat exchange of the fluid; a case that accommodates at least the syringe pump , the first pipe , the first electromagnetic valve , the second pipe , and the third pipe ; and a heat exchange unit accommodating part that accommodates the heat exchange unit , characterized in that the case further accommodates a branch pipe that branches the fluid, and the third pipe connects the first electromagnetic valve and the branch pipe , the heat exchange unit is formed to be a turning part obtained by extending the third pipe and winding the extended third pipe for a plurality of times so that a length of the third pipe is longer than a sum of a length of the first pipe and a length of the second pipe and the third pipe has a shape of increased surface area, such that the efficiency of heat exchange with ambient air is high and the heat exchange unit has heat exchanging capacity of eliminating a difference between a temperature of ambient air inside the case and a temperature of the fluid in the heat exchange unit , and the heat exchange unit accommodating part is provided on an upper side in the case . <EOS>