A printer 80 integrally comprises a printing section 81 for printing on a recording medium such as a cut sheet S and continuous paper L2 based on printing data transmitted from an external host unit H, a control panel 70 containing an indicator section for indicating operating states of the printing section 81, a display panel 60 for displaying data transmitted from the host unit H to the printing section 81 and instructed to be displayed, an interface 86 for transmitting/receiving signals between the host unit H and the printing section 81 and interfaces 87 and 62 for transmitting/receiving signals between the printing section 81 and the display panel 60. It is possible to securely prevent disagreement of printed content and displayed content and to realize down-sizing and simplification of the system structure by constructing a printer as described above.