Provided is a nonvolatile memory with less element deterioration and good
data retaining properties. In a nonvolatile memory formed by the
manufacturing steps of a complementary type MISFET without adding thereto
another additional step, erasing of data is carried out by applying 9V to
an n type well, 9V to a p type semiconductor region, and -9V to another p
type semiconductor region and setting the source and drain of data
writing and erasing MISFETs and data reading MISFETs at open potential to
emit electrons from a gate electrode to a p well by FN tunneling. At this
time, by applying a negative voltage to the p well having a capacitive
element formed thereover and applying a positive voltage to the p well
having the MISFETs formed thereover, a potential difference necessary for
data erasing operation can be secured at a voltage low enough not to
cause gate breakage.