A sample processing apparatus is disclosed. The apparatus comprises a sample processing section, a transporting section, an identification data acquirer and a system controller. When identification data of a washing fluid tube is acquired by the identification data acquirer, the system controller controls the transporting section to supply the washing fluid tube to the sample processing section. When the washing fluid tube arrives at the sample processing section, the sample processing section aspirates the washing fluid in the supplied washing fluid tube and performs a washing of at least one part of the sample processing section. The system controller prohibits the washing with the washing fluid tube if identification data of a sample tube is acquired after the identification data of the washing fluid tube is acquired and before the washing is started.