PURPOSE: To obtain a stamping apparatus which can form a stamp in which an imprinted character, etc., is not oozed out or not skipped.

CONSTITUTION: When a thermal head 90 is disposed in a perforating state, the position of the head 90 intruded into the printing surface of an impregnating material is always disposed at the position decided by a specific compression quantity Δt via the energizing force of a spring or the force of the spring in the state that the engaging plate of a heat dissipating plate is engaged with the upper end of the engaging hole of a carriage, and the perforating pressure σwhen the head 9 is brought into contact with the material without influence of the size and the elastic force of a stamping unit becomes a specific value.