The present invention suggests a method of providing subtitles for a 360 content, the method comprising: generating 360 video data captured by at least one camera; stitching the 360 video data; projecting the 360 video data to a 2D image; encoding the 2D image into a video stream; generating a 360 subtitle Supplemental Enhancement Information (SEI) message for signaling a subtitle for the 360 content; inserting the 360 subtitle SEI message into the video stream; and generating a broadcast signal including the video stream, and transmitting the broadcast signal.