A manufacturing method of a display device is disclosed. The method includes the following steps. A first substrate having a first region and a second region is provided. A second substrate is disposed on the first substrate. The second substrate is overlapping the first region. At least one drive IC is disposed on the second region. A protection layer is disposed on the second region. The protection layer is disposed enclosing the at least one drive IC. The protection layer has a maximum height larger than a maximum height of the at least one drive IC.