A punch includes first and second blade sections juxtaposed relative to each other in a direction parallel or substantially parallel to a feed direction of a sheet material. The first blade section protrudes downwardly from the second blade section with a step intervening therebetween and includes lower end edges on downstream and upstream sides of the feed direction, which define respective punching edges. The first blade section includes a lower end edge following the feed direction, which defines a first notching and punching edge. The notching and punching edge includes a portion intermediate of the feed direction representing a projecting shape. The second blade section includes a lower end edge on the upstream side, which defines a punching edge and also includes a lower end edge following the feed direction, which defines a notching and punching edge. The notching and punching edge is inclined gradually upwardly towards the upstream side.