Provided are a high voltage semiconductor device in which a field shaping layer is formed on the entire surface of a semiconductor substrate and a method of fabricating the same. Specifically, the high voltage semiconductor device includes a first conductivity-type semiconductor substrate. A second conductivity-type semiconductor layer is disposed on a surface of the semiconductor substrate, and a first conductivity-type body region is formed in semiconductor layer. A second conductivity-type source region is formed in the body region. A drain region is formed in the semiconductor layer and is separated from the body region. The field shaping layer is formed on the entire surface of the semiconductor layer facing the semiconductor layer.