PURPOSE: To obtain a constant printing state by bringing a printing surface to the same surface corresponding to the thickness of an enverope, by providing a guide plate for guiding an envelope and a press plate and pivotally mounting a lever to the press plate and connecting the same to a solenoid through a spring.

CONSTITUTION: An envelope receiving paper money or a check is received by an envelope port 6 and the charging of the envelope is detected by a detector 171. Thereafter, said envelope is fed to a printing part 165 and stopped in a state held between an upside feed belt 163 and a downside feel belt 163. When printing is applied to the envelope 200, a solenoid 304 is excited to be energized to the direction shown by an arrow M to pull a spring 303 and a press plate 301 rises to the direction shown by an arrow P through a lever 304 until contacts with a guide plate 200 for guiding the envelope 200 and printing can be performed in such a state that the gap between an index stamping part 180 and the printing part of the envelope 200 is kept constant. When no printing is performed, because the solenoid 304 is deenergized to be held under a free state, a press plate 201b is fallen to the direction shown by an arrow Q and brought to a state spaced apart from a guide plate 105a to wait for the suceeding printing.