A device and a method for realizing accurate TTML subtitle data display control are provided. A TTML subtitle data storage packet storing TTML subtitle data as payload of a MMT packet defined in the MMT format, and a signaling message including subtitle-related information corresponding to the TTML subtitle data are transmitted from a transmission device to a reception device. The signaling message defines therein a time mode (TMD) as subtitle display timing control mode, and an operation mode (OPM) of selectively performing instant display of subtitles or TTML description-based display thereof, and the reception device can conduct display control in a designated mode.