A skin adhesive member that helps a user maintain an appropriate posture while supporting muscles on the abdominal side. The skin adhesive member extends in a length direction and is adhered from an abdominal side to a back side across a side abdomen of the user, the skin adhesive member having a foundation portion, a first extension portion extending in the length direction from one end of the foundation portion and adhered to the back side, a second extension portion extending from another end of the foundation portion and adhered to the abdominal side, wherein the first extension portion includes at least a pair of belt portions.
