This invention relates to an encoding/transmitting apparatus that is used to transmit moving-picture data from a transmitting side to a receiving side through a transmission path and to subject the moving-picture data to streaming in the receiving side. The apparatus has an external-output request determining unit (16) that monitors the state of a network. If the network assumes an undesirable state, the unit (16) causes a multiplex output unit (15) to stop multiplexing data. When the network assumes a good state, the unit (15) starts multiplexing the data again. A video encoding unit (11) and an audio encoding unit (12) keep encoding data, whether the multiplex output unit (15) is multiplexing data or not. When the area occupied by encoded data in an encoded-video-data storage unit (13) and the area occupied by encoded data in an encoded-audio-data storage unit (14) exceed a predetermined value, the units (11) and (12) stop encoding data, and wait until the area occupied by encoded data sufficiently decreases.