An ultra-high voltage device has a high voltage path established from a high voltage N-well through a first metal layer to a second metal layer, and a contact plug electrically connected between the high voltage N-well and the first metal layer. The contact plug has a distributed structure on a horizontal layout to improve the uniformity of the ultra-high voltage device such that the current in the high voltage path will be more uniform distributed so as to avoid the localized heat concentration caused by non-uniform current distribution that would damage the ultra-high voltage device. Multiple fuse apparatus are preferably connected to the first metal layer individually. Each the fuse apparatus includes a poly fuse to be burnt down when an over-load current flows therethrough.