A sample rack transport apparatus for transporting a sample rack holding a container containing a sample is provided with a rack transport mechanism for transporting sample racks, and a control unit for controlling the operation of the transport mechanism. The transport mechanism has actuators, and the samples rack is transported by the operation of these actuators. The control unit is accommodated in a control box. The transport mechanism and control box are supported in a case. The control box is provided below the transport mechanism, and is configured so as to be slidably transferred into and from the case.