The present invention stores a cooled sample subjected to freezing treatment, or the like, while preventing the formation of condensation and frost-like substances and loads the sample into a sample holder for observation using a charged particle beam device. The present invention is provided with a main body for storing a sample and a lid unit mounted above the main body and is characterized in that the main body is divided into a first space and a second space by a partition member; the first space accommodates a cooling medium for cooling the sample; the second space has, disposed therein, a heating unit for heating the cooling medium accommodated in the first space; and the lid unit has, formed therein, a discharge port for discharging the gas generated by the heating of the cooling medium to the outside.