A catheter with a valve is disclosed that allows smooth flow of a solution in both directions when a solution is flowing from the inside of a catheter towards the outside of a catheter and when a solution is flowing from the outside of a catheter towards the inside of a catheter. The catheter includes a tubular body 12 made of an elastic and flexible synthetic resin material. The catheter is equipped with a valve B1 having a slit 16 that can be opened and closed passing through the outer surface 12b of the tubular body from the inner surface 12a of the tubular body. The catheter is also provided with the movable wall 15 sunken towards the inside of the tubular body 12 at an end tip member region 14 of the tubular body 12. The location where the movable wall 15 exists has a structure with differences in hardness in the thickness direction of the tubular body 12. In the cross-sectional surface perpendicular to the center axis C1 of the tubular body 12, the movable wall 15 has a wall central member P1 located at a position close to the center axis C1 and a movable wall tip member P2 located at a position far from the center axis C1. The slit 16, is formed on the movable wall tip member P2.Se describe un catéter con una válvula que permite el flujo uniforme de una solución en ambas direcciones cuando una solución está fluyendo desde el interior de un catéter hacia el exterior de un catéter y cuando una solución está fluyendo desde el exterior de un catéter hacia el interior de un catéter. El catéter incluye un cuerpo tubular 12 hecho de un material de resina sintética elástico y flexible. El catéter está equipado con una válvula B1 que tiene una abertura 16 que puede abrirse y cerrarse pasando a través de la superficie exterior 12b del cuerpo tubular desde la superficie interior 12a del cuerpo tubular. El catéter también está provisto con la pared móvil 15 hundida hacia el interior del cuerpo tubular 12 en una región de miembro de punta de extremo 14 del cuerpo tubular
