To provide a trunk supporter that can be worn without pressing the abdomen and inner wear provided with the trunk supporter. An X-shaped belt having a belt-shaped lower band portion that is wound and fixed around a user's pelvis and a pair of one end portions joined to the lower band portion and presses the vicinity of the user's waist. A pair of one end portions of the intermediate band portion, comprising: a stretchable intermediate band portion; and a pair of upper band portions that are joined to a pair of other end portions of the intermediate band portion and are wound around and fixed to a user's chest. Is joined to the range of the user's pelvis lateral position in the lower band portion to the vicinity of the front position thereof, and the pair of upper band portions are separated in the deployed state and extend in opposite directions to each other, and the chest of the user Trunk supporter configured to be wound and fixed near the fifth to tenth ribs. [Selection] Figure 1【課題】腹部を圧迫することなく着用できる体幹サポーターおよびそれを備えたインナーウエアを提供すること。【解決手段】使用者の骨盤の周囲に巻き付けられ固定される帯形の下バンド部と、前記下バンド部に接合された一対の一端部を有し使用者の腰部付近を押圧するX形の伸縮性中間バンド部と、前記中間バンド部が有する一対の他端部に接合され使用者の胸部に巻き付けられ固定される一対の上バンド部とを備え、 前記中間バンド部の前記一対の一端部は、前記下バンド部における使用者の骨盤真横位置からその近傍前方位置の範囲に接合され、 前記一対の上バンド部は、展開状態において分離しかつ相互に反対方向に延びると共に、使用者の胸部の第5~第10肋骨付近に巻き付けられ固定されるよう構成された体幹サポーター。【選択図】図1