According to one embodiment, a storage device includes a control apparatus and a stocker. The control apparatus writes data to or reads data from a storage medium that includes a plurality of non-volatile memory chips. The stocker stores a plurality of the storage media that are detached from the control apparatus. The control apparatus includes a first temperature control system. The first temperature control system raises temperature of the storage medium to a first temperature or higher. The stocker includes a second temperature control system. The second temperature control system cools the storage medium to a second temperature or lower. The second temperature is lower than the first temperature.