An n-type drift region includes an active element region and a peripheral
region. A p-type base region is formed at least in the active element
region. A trench-type gate electrode is formed in each of the active
element region and the peripheral region. An n-type source region formed
in the base region. A plurality of p-type column regions is selectively
formed separately from one another in each of the active element region
and the peripheral region. In a peripheral region, a p-type guard region
is formed below the gate electrode. In the active element region, the
p-type guard region is not formed below the gate electrode. As a result,
it is possible to hold the breakdown voltage in the peripheral region at
a higher level than in the active element region while maintaining the
low ON resistance due to a superjunction structure and to raise the
breakdown voltage performance of the semiconductor device.