To provide a printer for a cellular telephone, which can print information to be printed by rapidly selecting it from electronic mail information accumulated in the cellular phone.

This printer is equipped with a connector 3 which is to be connected to the cellular phone 30, a printing part 4 for printing prescribed information; a computing part 5 into which the information of the cellular phone 30 is input via the connector 3, which performs prescribed arithmetic processing according to the information, and which can output a signal for displaying the prescribed electronic mail information on a display of the cellular phone 30 and a signal for making the printing part 4 print the prescribed electronic information; an operation part 7 which comprises a display operation button for displaying the prescribed electronic mail information, accumulated in the cellular phone 30, on the display of the cellular phone 30, a selection operation button for selecting an electronic mail file to be printed from the displayed electronic mail information, and a printing operation button for making the printing part 4 print the electronic mail file selected by the selection operation button; and a casing 2.