To provide a semiconductor storage unit that has a simple structure requiring only a small number of processes to produce, and is provided with a gate insulating film having a memory function. The semiconductor storage unit has a semiconductor layer, two diffusion layer regions forming a source region and a drain region, which are formed on the semiconductor layer, a channel region fixed between the two diffusion layer regions, a gate insulating film that is formed on the channel region, and made of a silicon oxide film containing carbon atoms of 0.1 to 5.0 atomic percent, and a gate electrode formed on the gate insulating film.