A sample processing apparatus which has a transporting device; a sample processing device, the transporting device has a first transport path; a second transport path; a rack moving mechanism for moving the sample rack from the first transport path to the second transport path; a guide member, movable in vertical directions, for allowing the sample rack to move from the first transport path to the second transport path when the guide member is at a predetermined position, and for preventing the sample rack being transported on the first transport path or the second transport path from deviating from the transport path when the guide member is above the predetermined position; and a drive source for moving the guide member in vertical directions. Also, a sample transporting device, and a sample rack transporting method.