A first p type semiconductor region is provided between an n type drift region surrounding a drain region and an n type buried region, and a second p type semiconductor region is provided between the first p type semiconductor region and a p type well region surrounding a source region so as to overlap the first p type semiconductor region and the p type well region. Negative input breakdown voltage can be ensured by providing the first p type semiconductor region over the n type buried region. Further, potential difference between the source region and the first p type semiconductor region can be increased and the hole extraction can be performed quickly. Also, a path of hole current flowing via the second p type semiconductor region can be ensured by providing the second p type semiconductor region. Thus, the on-breakdown voltage can be improved.