To provide a document bag in which a PDA is put for carrying with documents and enables a user to easily execute simple operation and extension of functions of the PDA without taking out the PDA preventing the document from scattering.

This bag for a PDA (10) is equipped with a window (13) with a size through which operation and display of the PDA (10) can be confirmed and the PDA behind the window (13). A stylus holder (38) is equipped near by the window (13). A protective lid (14) with a stylus hole (39) or a first lid (67) is equipped in front of the window (13). A through hole shape extension terminal window (35) or an external extension terminal (21) or an external IR port (30) is equipped on any of six faces of the document bag. Accordingly the document bag is free from accidents of scattering documents and enables a user to operate the PDA even in a short time waiting for a tram, and the PDA is enabled to connect to periphery equipment to realize easy extension operation of functions.