There is provided a transmitting apparatus for transmitting data, which includes: compressing means compressing data to be transmitted; packetizing means packetizing the data compressed by the compressing means; a buffer for accumulating the data which are packetized; transmitting means transmitting the data accumulated in the buffer; clearing means clearing the buffer at each time that a predetermined time is lapsed; number-of-data counting means counting the number of the data which are not transmitted within the predetermined time; time measuring means measuring a transmission idle time which lasts from a transmission completion time to a clearing time, in a case where all of the data accumulated in the buffer are transmitted before the predetermined time is lapsed; and compression controlling means controlling a compression rate of the data, depending on the number of the data counted or the transmission idle time measured.