In an LDMOS transistor, a channel length is reduced to increase a saturation current without causing an off-state breakdown voltage optimized in terms of trade-off between an on-resistance and the off-state breakdown voltage. A short channel region is selectively formed between an element isolation film and a low-concentration body region in which a channel is formed such that the short channel region is located immediately below a gate oxide film. The short channel region has a conduction type opposite to that of the low-concentration body region and has a carrier concentration higher than that of the low-concentration body region. The body region is retreated by the presence of the short channel region toward a high-concentration source region.