How to say "interior" in Japanese

• 中なかJLPT N5approx.Common
  nounThe general word for the inside of something: a room, a box, the body. For 'interior' in this plain spatial sense it is usually the natural choice.
  彼かれは自分じぶんのお金かねを全部ぜんぶ箱ばこの中なかに入いれた。↗

  He put all his money in the box.
• 奥おくJLPT N3approx.Common
  nounCovers 'interior' as the innermost or back part: the depths of a forest, the back of a drawer or one's throat. It points to the far, deeper inside rather than the whole interior.
• 内部ないぶJLPT N1approx.Common
  no-adjectiveCovers 'interior' as the inside of a building, machine, or organization, in contrast with the exterior — the closest match when 'interior' means the internal part as a whole.
  この図解ずかいは地球ちきゅうの深ふかい内部ないぶを示しめしている。↗

  The illustration shows the deep interior.
• 中身なかみJLPT N2approx.Common
  nounMeans the contents or filling — what a box or container holds — rather than the interior space itself. For spatial 'interior' this is seldom the word you want; it is really 'contents'.
  財布さいふの中身なかみをこの袋ふくろに空あけなさい。↗

  Empty the purse into this bag.
• 内側うちがわCommon
  no-adjectiveRefers to the inner side or the part nearer the inside, typically contrasted with the outer side. For 'interior' as the whole inside of something, 中 or 内部 is more typical.
  ドアは内側うちがわから鍵かぎがかかっていた。↗

  The door was locked from within.

Use 中 for the general inside of something, 内部 for the interior of a building, machine or organization, 奥 for the deeper inner part or depths, 内側 for the inner side, and 中身 only for contents.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 中なかinside
• 奥おくinner part
• 内部ないぶinterior
• 中身なかみcontents
• 内側うちがわinside
• 内装ないそうinterior design
• インテリアinterior (of building, room, vehicle, etc.)
• 内面ないめんinside
• 奥地おくちinterior
• 車室しゃしつcompartment (of a train)
• 内辺ないへんinside
• 内なるうちなるinner (self, voice, man, etc.)
• 国内的こくないてきinternal (to a country)
• 奥深いおくふかいdeep (of a cave, etc.)
• インin
• 内地ないちinland
• 腹はらinside