A chip on film for a display device, the chip on film includes: a base substrate; a lead wire disposed on the base substrate; and a driving chip connected to the lead wire, wherein the lead wire includes: a first lead part having a first thickness; and a second lead part disposed between the first lead part and the driving chip and having a second thickness greater than the first thickness, the second lead part being connected to the driving chip. The first lead part and the second lead part include a same material.