A mobile information apparatus (10, 20) comprising: two displays (11, 12) whose display surfaces (22, 25) are arranged side by side, the two displays including a first display and a second display, the display surfaces (22, 25) of said two displays are arranged on both sides of a predetermined axis; a measurement section (28, 28', 51) configured to measure orientation information about a relative angle between the display surfaces; and a control section configured to determine the display surface (22, 25) that the user is viewing from among said two displays (11, 12), configured to cause the display surface of displays other than the display surface determined as being viewed by the user to become darker than the display surface on the display that is determined as being viewed by the user; wherein this determination is conditional on the mobile information apparatus being in an open state, detected by a change in the relative angle over time obtained from the orientation information detected by said measurement section (28, 28', 51), the change in the relative angle over time being a turning operation around the predetermined axis; and wherein said measurement section (28, 28', 51) is further configured to take an image in front of the display surface of said first display; and said control section is further configured to determine that the user is looking at the display surface of said first display if the image taken by said measurement section shows that the user is directly facing the display surface of said first display, and to determine that the user is viewing at the display surface of said second display if the image shows that the user is facing the display surface of said second display. two displays (11, 12) whose display surfaces (22, 25) are arranged side by side, the two displays including a first display and a second display, the display surfaces (22, 25) of said two displays are arranged on both sides of a predetermined axis; a measurement section (28, 28', 51) configured to measure orientation information about a relative angle between the display surfaces; and a control section configured to determine the display surface (22, 25) that the user is viewing from among said two displays (11, 12), configured to cause the display surface of displays other than the display surface determined as being viewed by the user to become darker than the display surface on the display that is determined as being viewed by the user; wherein this determination is conditional on the mobile information apparatus being in an open state, detected by a change in the relative angle over time obtained from the orientation information detected by said measurement section (28, 28', 51), the change in the relative angle over time being a turning operation around the predetermined axis; and wherein said measurement section (28, 28', 51) is further configured to take an image in front of the display surface of said first display; and said control section is further configured to determine that the user is looking at the display surface of said first display if the image taken by said measurement section shows that the user is directly facing the display surface of said first display, and to determine that the user is viewing at the display surface of said second display if the image shows that the user is facing the display surface of said second display.