Correctional institutions include prisons,juvenile prisons,detention houses,juvenile training schools,juvenile classification homes and a women's guidance home.Among them,prisons,juvenile prisons,and detention houses are collectively called penal institutions.As of April1,2005,there were74penal institutions(59prisons,eight juvenile prisons and seven detention houses)and113branches(six prison branches and107branch detention houses).
  Prisons and juvenile prisons house those offenders sentenced to imprisonment with or without labor and those sentenced to penal detention for the execution of their sentences and provide necessary treatment for them.Detention houses mainly house untried inmates(persons arrested or imprisoned by reason of a criminal charge against them,who are detained either in police custody or in prison custody but have not yet been tried and sentenced;hereinafter the same).For separation and the necessity for treatment of sentenced inmates(those confined in penal institutions for the execution of sentences of imprisonment with or without labor or penal detention;hereinafter the same),some prisons(Tochigi,Kasamatsu,Wakayama,Iwakuni,Fumoto Prisons,and Sapporo and Fukushima Branch Prisons)house only female inmates,and four medical prisons provide medical care to inmates with physical or mental disorders.
  Penal institutions have workhouses in which offenders who are unable to pay fines or minor fines are detained,and except for some institutions also have houses of Kanchi confinement in which persons subject to confinement as the punishment for contempt of court(Kanchi confinement)under the provision of Article2of the Law for Maintenance of Order in Court-Room(Law No.286of1952)etc.are detained.
  Staff who work at penal institutions are prison officers(officials with custodial authority under the Prison Law)as well as technical and educational officers.