A cable assembly comprising: a cable (103, 103A); a connector (101, 102) that is provided at an end of the cable (103, 103A, 503) 103A) in a direction in which the cable (103, 103A) extends; a plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) configured to transmit an electric signal; and a plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) configured to transmit an optical signal, wherein the plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided so as to extend across the cable (103, 103A) and the connector (101, 102), wherein the connector (101, 102) has a plurality of electric terminals (116, 126) configured to be electrically connected to the respective plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g); each of the plurality of electric terminals (116, 126) is arranged in compliance with a high definition multimedia interface - HDMI (registered trademark) standard; characterized in that the cable (103, 103A) is a flat cable, and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided so that at least one of the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) is provided at each of ends of the cable (103, 103A) and the connector (101, 102) in a width direction perpendicular to the direction in which the cable (103, 103A) extends, and the plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) are provided inside the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) in the width direction; and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided outside the plurality of electric terminals (116, 126) in the width direction in the connector (101, 102). a cable (103, 103A); a connector (101, 102) that is provided at an end of the cable (103, 103A, 503) 103A) in a direction in which the cable (103, 103A) extends; a plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) configured to transmit an electric signal; and a plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) configured to transmit an optical signal, wherein the plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided so as to extend across the cable (103, 103A) and the connector (101, 102), wherein the connector (101, 102) has a plurality of electric terminals (116, 126) configured to be electrically connected to the respective plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g); each of the plurality of electric terminals (116, 126) is arranged in compliance with a high definition multimedia interface - HDMI (registered trademark) standard; characterized in that the cable (103, 103A) is a flat cable, and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided so that at least one of the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) is provided at each of ends of the cable (103, 103A) and the connector (101, 102) in a width direction perpendicular to the direction in which the cable (103, 103A) extends, and the plurality of electric transmission lines (136a, 136b, 136c, 136d, 136e, 136f, 136g) are provided inside the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) in the width direction; and the plurality of optical transmission lines (113a, 113b, 113c, 113d, 123a, 123b, 123c, 123d) are provided outside the plurality of electric terminals (116, 126) in the width direction in the connector (101, 102).