Sample storage, in which barcodes and two-dimensional codes printed on the outer surface of the sample storage can be read correctly. A storage tube 110 is transparent, comprising a top opening. An opaque writable outer element 120 covers storage tube 110 throughout from the bottom surface to the side surface. An opaque writable outer element 120 is a medium on which coded information that can be read by optical reading is written. The opaque writable outer element 120 is pushed in and irreversibly fixed to the storage tube 110 by a locking mechanism. At least one window 125 is provided, which enables a sample 200 contained to be observed, with the opaque writable outer element 120 installed outside. Accordingly, coded information written on the opaque writable outer element 120 can be read, and sample 200 observed through the window 125.