PROBLEM TO BE SOLVED: To provide a biological organ dilator which has a portion capable of moving and a portion not capable of moving in time of an opening operation of a self-dilation type stent, and is easy to recognize the movable portion and the non-movable portion, and an opening part for a guide wire port formed in the non-movable portion.SOLUTION: This biological organ dilator 1 includes: a distal end side tube 2 a base end side tube 3 a non-movable tube 8 wherein a base end part of the distal end side tube and a distal end part of the base end side tube are fixed and which has an opening 23 in the base end part a movable portion 4 including a stent storing cylindrical member 5 capable sliding to the base end direction a stent 30 stored in the cylindrical member 5 and a traction wire 6 for moving the movable portion 4 including the cylindrical member 5 to the base end side. The non-movable tube 8 has a color distinguishable from a base end side portion 9 rather than the movable portion 4 and the non-movable tube 8 from a distal end part to the base end part wherein the opening for a guide wire port is positioned.
