The present invention has an object of providing a connection structure capable of easily connecting an LED component to a flat cable. An LED unit 1 includes an upper case 7, a pierce terminal 6, a lower case 9 and an intermediate terminal 5. An LED chip 3 is pressed to the pierce terminal 6 by a convexed spring 51 to electrically connect the LED chip 3 to the flat cable 100. Conductors 101 included in the flat cable 100 are formed of phosphor bronze formed of tin (Sn), phosphorus (P), copper (Cu) and unavoidable impurities and having a tensile strength of 480 to 550 MPa, whereas a pierce plate 63 of the pierce terminal 6 piercing through the conductor 101 is formed of a copper alloy, which is a high strength conductive member having a higher strength than that of the conductor 101 and having conductivity.