A walk supporting device includes a seating member on which a user is seated in a straddling manner and a pair of left and right leg links that support the seating member from below. Each of the leg links is coupled to the seating member to freely swing in a horizontal direction. The seating member is prevented from rolling around a support shaft serving as a swing fulcrum in the horizontal direction of the leg link to improve stability in the horizontal direction of the seating member. A stopper member coupled to the seating member is inserted between joint sections at upper ends of left and right leg links supported by the support shaft. A regulating mechanism that regulates the seating member in a posture orthogonal to an equiangular bisector of an angle in the horizontal direction formed by the left and right leg links may be provided.