An image display device comprising: a display part configured to display an image; a user identifying part configured to perform personal identification to identify personal identification information; a hold detecting part configured to detect whether the image display device is held by hand; and a control part configured to display an image on the display part upon a display request when the user identifying part identifies personal identification information obtained upon the display request as personal identification information of an authorized user who is allowed to use the image display device, to continue displaying the image on the display part as long as the hold detecting part detects that the image display device is held by hand, and to erase the image on the display part when the user identifying part fails to identify the personal identification information of the authorized user by a personal identification performed upon detecting by the hold detecting part that the image display device is not held by hand; wherein the hold detecting part includes a first hold detecting member provided on a front surface side of the image display device, said front surface side being the same side as a side of the display part on which the image is displayed, and a second hold detecting member provided on a back surface side of the image display device, said back surface side being on an opposing side of the image display device to the front surface side; and is configured to detect that the image display device is held by hand when holding positions detected by the first and second hold detecting members are on the same straight line perpendicularly passing through the front and back surfaces and wherein the control part is configured to continually display the image on the display part after the image display device is transferred between the authorised user and an unauthorised user for as long as the image display device remains in a continuous handheld state. a display part configured to display an image; a user identifying part configured to perform personal identification to identify personal identification information; a hold detecting part configured to detect whether the image display device is held by hand; and a control part configured to display an image on the display part upon a display request when the user identifying part identifies personal identification information obtained upon the display request as personal identification information of an authorized user who is allowed to use the image display device, to continue displaying the image on the display part as long as the hold detecting part detects that the image display device is held by hand, and to erase the image on the display part when the user identifying part fails to identify the personal identification information of the authorized user by a personal identification performed upon detecting by the hold detecting part that the image display device is not held by hand; wherein the hold detecting part includes a first hold detecting member provided on a front surface side of the image display device, said front surface side being the same side as a side of the display part on which the image is displayed, and a second hold detecting member provided on a back surface side of the image display device, said back surface side being on an opposing side of the image display device to the front surface side; and is configured to detect that the image display device is held by hand when holding positions detected by the first and second hold detecting members are on the same straight line perpendicularly passing through the front and back surfaces and wherein the control part is configured to continually display the image on the display part after the image display device is transferred between the authorised user and an unauthorised user for as long as the image display device remains in a continuous handheld state.