ANALYZER

PROBLEM TO BE SOLVED: To provide an analyzer capable of simplifying a setting work of a reagent container to a container holding part by a user even more.SOLUTION: An analyzer 1 comprises: a container holding part 13 which holds a plurality of reagent containers 21(22); a mounting chamber 140 which includes a mounting part 41 on which the reagent container 21(22) is mounted and a container detecting section 42 which detects the reagent container 21(22) mounted on the mounting part 41 inside thereof; a door part 45 which opens/closes an entrance of the mounting chamber 140; a transport mechanism 42 which grips the reagent container 21(22) mounted on the mounting part 41 and transports the container to the container holding part 13; and a control section 2a which, as the container detecting section 13 detects the reagent container 21(22) when the door part 45 is closed, allows the transport mechanism 42 to start transporting the reagent container 21(22).