A termination structure for high-speed transmission line includes a high-speed transmission line including a signal line configured to transmit a signal, an insulation which covers the signal line and an external conductor disposed at an outer periphery of the insulation, and a termination terminal disposed at a terminal of the high-speed transmission line. The termination terminal includes a holder disposed sandwiching the external conductor exposed at the terminal of the high-speed transmission line from both sides. The holder includes a holding part to hold the high-speed transmission line and is electrically connected to the external conductor. The holding part is formed so as to have a shape along an outer shape of the external conductor.