To provide a stamping apparatus that automatically stamps an important document with a certification seal (original seal) under proper stamping conditions so as to obtain a constant imprint of the seal.

The stamping apparatus 1 includes: an unused plate storing part 3 in which an unused rolled mimeograph paper 4 is stored; conveying means 9, 16 for drawing the mimeograph paper and conveying it; a plate making part 6 for making a plate of a desired certification seal on the drawn mimeograph paper; a paper feed part 18 for supplying an original 45 which is to be stamped with the certification seal; a stamping part 10 for stamping the original with the certification seal using the prepared plate of the certification seal; and a stamped plate storing part 17 in which the mimeograph paper used for printing of the certification seal is rolled and stored in continuation to the mimeograph paper of the unused plate storing part. Stamping with the certification seal is always possible under the constant conditions.