A control apparatus of a network camera includes a determination unit configured to determine an overlapping state of a cursor with each of a slider bar and a slider thumb, which configure a slider control, on a display screen of a display unit, a decision unit configured to decide information that relates to the slider control and is to be displayed on the display unit, based on a condition corresponding to a result of the determination by the determination unit, a display control unit configured to display the information decided by the decision unit on the display unit, and a transmission unit configured to transmit, to the network camera, a control signal that corresponds to a position of the slider thumb and is changed in response to input of an instruction by a user.