There are provided an external cylinder for a probe equipped in a cryosurgical apparatus and a therapeutic-device unit, which are able to protect normal cells near a lesion, provide higher heat efficiency for the freeze and thawing, and simplify the structure. The external cylinder for the probe equipped in the cryosurgical apparatus and the therapeutic-device unit which includes the external cylinder for the probe equipped in the cryosurgical apparatus are provided. The external cylinder includes a given range in which the freezing gas enables an ice ball to be formed on an outer circumference including the distal end portion and adiabatic means arranged in a range other than the given range so as to prevent heat from being exchanged between the inner space and an outside.
