There is provided an end structure of a nozzle (11) including a gas-flow passage (13) communicable with an opening (104) provided through a bottom of a container (100) configured to contain an object, the nozzle (11) configured so that gas is injected into or discharged from the container (100) through the gas-flow passage (13) and the opening (104). The end structure includes a contact portion (19) provided at an upper end portion of the nozzle (11) and around the gas-flow passage (13), and the contact portion (19) is configured to be brought into contact with a contacted portion (103) provided around the opening (104). The contact portion (19) includes a flat portion (19b) and protruding portions (19a and 19c) each protruding upward relative to the flat portion (19b), and the flat portion (19b) is made of material softer than that of the protruding portions (19a and 19c).