To provide an automatic information sending system using a personal digital assistant, allowing a member wanting service and information of a store or the like to easily and accurately transmit an E-mail address.

The automatic information sending system is provided with a member database 1 of a member organization, an automatic ID sending device 7 provided with an automatic communication executing means 3 having a connecting part to the personal digital assistant 2 and provided with a program for automatically sending E-mail from the personal digital assistant and a card reader 5 for inputting a member ID, and a terminal server 8 with a sending destination address set in the program and connected to the member database. The automatic ID sending device sends the member ID as E-mail to the terminal server from the personal digital assistant, the terminal server records the mail address and the member ID from the received E-mail, and it sends E-mail of information or the like desired by the member on the basis of data of the member acquired from the member database by using the acquired member ID.