An indwelling balloon catheter for an endoscope is provided with a flexible tube including a first lumen and a second lumen, the first lumen and the second lumen being arranged in parallel with each other and extending in an axial direction of the flexible tube over an entire length thereof, and a connector provided with a first connecting pipe and a second connecting pipe which protrude from a body of the connector, protruded portions of the first connecting pipe and the second connecting pipe being configured to be removably inserted into the first lumen and the second lumen, respectively. A cross sectional shape of the first lumen is a non-circular shape, a cross sectional shape of the first connecting pipe corresponding to the cross sectional shape of the first lumen. The first connecting pipe protrudes longer from the connector than the second connecting pipe.