A medical device includes a first region including a distal end, a second region adjacent to the first region on a proximal side of the first region, a third region adjacent to the second region on a proximal side of the second region, and a fourth region adjacent to the third region on a proximal side of the third region. In the second region, the medical device is configured such that when bending reaction force values are acquired at a plurality of measurement points arranged in an axial direction, a product of an average value of the bending reaction force values at the measurement points and a standard deviation of the bending reaction force values is 80 mN2 or less.