<；P>；PROBLEM TO BE SOLVED: To provide a catheter allowing an operator to operate a closing member with a small force without using a specific inflatable adapter and simply execute the operation of a seal part, and being easily manufactured with no strict tolerance in the manufacturing process. <；P>；SOLUTION: This catheter for dilating or closing a living body lumen is provided with a balloon, a tubular body having an inflation lumen 201 allowing the movement of fluid for inflating or deflating the balloon, and a fluid seal section 202 sealing the fluid, and is characterized in that the structure of the fluid seal section 202 comprises a movable closing member 203 having a tapered section 203A whose outside diameter becomes gradually smaller toward one end and a closing section 204 fitted with the tapered section 203A, and has an automatic control device. <；P>；COPYRIGHT: (C)2007,JPO&INPIT
