FinFET devices and methods of forming the same are disclosed. One of the FinFET devices includes first fins, second fins, a first gate strip, a second gate strip and a comb-like insulating structure. The first and second fins are disposed on a substrate. The first gate strip is disposed across the first fins. The second gate strip is disposed across the second fins. The comb-like insulating structure is disposed between the first gate strip and the second gate strip and has a plurality of comb tooth parts. In some embodiments, each of the comb tooth parts has a middle-wide profile.