Abstract: Provided is a manufacturing method for a power management semiconductor device or an analog semiconductor device both including a CMOS. According to the method, a substance having high thermal conductivity is additionally provided above a semiconductor region constituting a low impurity concentration drain region so as to expand the drain region, which contributes to a promotion of thermal conductivity (or thermal emission) in the drain region during a surge input and leads to suppression of local temperature increase, to thereby prevent thermal destruction. Therefore, it is possible to manufacture a power management semiconductor device or an analog semiconductor device with the extended possibility of transistor design.