A conductive member comprising: a flat conductor having a substantially rectangular cross section; first and second cover members (1, 3) disposed so as to face each other with respect to front and back surfaces of the flat conductor, and sandwiching the flat conductor in a plate thickness direction of the flat conductor to cover the flat conductor, the first and second cover members (1, 3) being made of insulating resin; a locking portion (21a, 21b) provided on the first cover member and protruding toward the second cover member; and an engagement portion provided on the second cover member, and configured to hold the first and second cover members (1, 3) in a state that the flat conductor is sandwiched between the first and second cover members (1, 3), wherein the engagement portion engages with the locking portion (21a, 21b) which passes through a through hole provided in a central portion of the flat conductor, wherein the engagement portion has a penetration opening, and wherein the locking portion (21a, 21b) has a pair of flexible lock pieces (21a, 21b) which are respectively engaged with opening edges (4c, 4d) of the penetration opening which face each other; characterized in that the first cover member has a penetration opening and the pair of flexible lock pieces (21a, 21b) which protrude toward the second cover member from open edges (2a, 2b) of the penetration opening of the first cover member which face each other; wherein the second cover member has a pair of flexible lock pieces (41a, 41b) which protrude toward the first cover member from opening edges (4a, 4b) of the penetration opening of the second cover member, where the pair of flexible lock pieces (21a, 21b) of the first cover member are not engaged; wherein the pair of flexible lock pieces (41a, 41b) of the second cover member are engaged with opening edges (2c, 2d) of the penetration opening of the first cover member, where the pair of flexible lock pieces (21a, 21b) of the first cover member are not provided, of the penetration opening of the first cover member. a flat conductor having a substantially rectangular cross section; first and second cover members (1, 3) disposed so as to face each other with respect to front and back surfaces of the flat conductor, and sandwiching the flat conductor in a plate thickness direction of the flat conductor to cover the flat conductor, the first and second cover members (1, 3) being made of insulating resin; a locking portion (21a, 21b) provided on the first cover member and protruding toward the second cover member; and an engagement portion provided on the second cover member, and configured to hold the first and second cover members (1, 3) in a state that the flat conductor is sandwiched between the first and second cover members (1, 3), wherein the engagement portion engages with the locking portion (21a, 21b) which passes through a through hole provided in a central portion of the flat conductor, wherein the engagement portion has a penetration opening, and wherein the locking portion (21a, 21b) has a pair of flexible lock pieces (21a, 21b) which are respectively engaged with opening edges (4c, 4d) of the penetration opening which face each other; characterized in that the first cover member has a penetration opening and the pair of flexible lock pieces (21a, 21b) which protrude toward the second cover member from open edges (2a, 2b) of the penetration opening of the first cover member which face each other; wherein the second cover member has a pair of flexible lock pieces (41a, 41b) which protrude toward the first cover member from opening edges (4a, 4b) of the penetration opening of the second cover member, where the pair of flexible lock pieces (21a, 21b) of the first cover member are not engaged; wherein the pair of flexible lock pieces (41a, 41b) of the second cover member are engaged with opening edges (2c, 2d) of the penetration opening of the first cover member, where the pair of flexible lock pieces (21a, 21b) of the first cover member are not provided, of the penetration opening of the first cover member.