Endoscope with bendable insertion unit

An endoscope comprising:

• an insertion unit including an imaging unit;
• and
• an operation unit configured to bend a part of the insertion unit,
• wherein at least a part of the insertion unit includes a tube formed of a resin, the tube including a plurality of channels formed of the resin included in the tube,
• wherein the resin forms a non-porous resin layer having a porosity of 0%,
• wherein the non-porous resin layer is provided on a radially outer surface of the tube and in a part of the tube close to the outer surface,
• the endoscope comprising:
• a single-use portion including the tube that is replaced for each use;
• and
• a reusable portion including the imaging unit that is collected for each use to be reused
• wherein at least a part of the resin is a porous resin,
• wherein the porous resin has a porosity changing in a radial direction of the tube and the outer surface of the tube have a porosity smaller than that of the center of the tube.