A thin film transistor substrate including a thin film transistor having a drain electrode with an electrode portion, which overlaps with a semiconductor layer, and an extended portion, which extends from the electrode portion and has a portion overlapping with a storage electrode or storage electrode line. A passivation layer is arranged on the drain electrode, and it has a contact hole that partially exposes the extended portion of the drain electrode without exposing a step in the extended portion caused by the storage electrode or storage electrode line. A pixel electrode is arranged on the passivation layer and is electrically connected with the extended portion of the drain electrode through the contact hole.