Provided is a medical device and a treatment method that can effectively remove an object in a body lumen.This medical device (10) for removing an intravascular thrombus (T) includes: a rotatable tubular driving shaft (20); a cutting part (40) that is provided on a distal side of the driving shaft (20), rotates together with the driving shaft (20), and cuts the thrombus (T); and a second cutting part (210) that is disposed near the distal side of the driving shaft (20), inward of the cutting part (40).