An external input apparatus connected with a communication terminal delivering conference data including voice or video to another set of equipment connected via a network is disclosed. The external input apparatus includes a first display part for displaying an image; an operation reception part for receiving a user's operation; an image obtaining part for obtaining image data of the image; an image data transmission part for transmitting the image data to the other set of equipment by using the communication terminal; a transition information storage part for registering, according to display control information reported by the communication terminal, a transition condition of a share menu which is used for receiving a sharing control operation for the image data; and a menu control part for displaying, by using the first display part, the share menu determined according to the display control information obtained from the communication terminal and the transition condition.