To provide a cutting blade and a cutter capable of cutting a pipe-shaped material to be cut so that a cutting surface may be a substantially completely flat surface and saving resources by reducing cutting man-hours and reducing portions to be abandoned in a cutting process.

This cutting blade 1 includes two circular-shaped end faces 5a and 5b. When the cutting blade 1 is viewed from a side surface, that is, a direction perpendicular to a line for connecting the end face 5a and the end face 5b, the end face 5a and the end face 5b are the flat surfaces parallel to each other. In a region held by the end face 5a and the end face 5b, an inclined surface 6a is provided so that thickness close to a center part 21 of a substrate 2 may be thicker from an outer peripheral end 20a of the end face 5a toward the center part 21 of the substrate 2, while an inclined surface 6b is provided so that thickness close to the center part 21 of the substrate 2 may be thicker from an outer peripheral end 20b of the end face 5b toward the center part 21 of the substrate 2.