To apply sufficient fastness to ink by providing a pressing roller which has a certificate stamp on an outer circumferential face and presses the certificate stamp at a predetermined position of a transferred paper, and filling ink through intermittent butting to the certificate stamp of the pressing roller.

When a paper is inserted from an external apparatus to a paper transfer part 1, a control part 4 analyzes a certificate stamp press signal from the external apparatus and judges the presence/absence of a certificate stamp. When the certificate stamp is present, it is detected at which of pressing parts 2, 3 the stamp is provided. For instance, if a certificate stamp 2a of the pressing part 2 is designated, a pressing driving motor 2E is driven and a clutch 2Be is also started. When a pressing roller 2A is in a standby state, the clutch 2Be is controlled to make the certificate stamp 2a and an ink-containing member 2Ba come in touch with each other. Then, a paper transfer roller mechanism is driven to transfer the paper to the pressing part 2, and the ink of the ink- containing member 2Ba is transferred to the certificate stamp 2a.