A tissue resection method of resecting a portion of a hollow organ includes a first step of specifying a position and a range of a resection target tissue from the inside of the hollow organ and showing the position and the range in a visually recognizable manner from the inside of a body cavity a second step of bringing a bioabsorbable member introduced into the body cavity into contact with the resection target tissue and pressing the resection target tissue, thereby inverting the resection target tissue to the inside of the hollow organ and a third step of resecting the inverted resection target tissue over all layers from the inside of the hollow organ and performing anastomosis of a hole formed in the hollow organ from the inside of the hollow organ.
