Abstract
In this report, I inspected the developments of rice cookers before they were controlled by microcomputer, based on newspaper advertisements. As a result, it becomes clear that; 1) Broadly speaking, rice cookers were improved in pursuit of convenience and good taste of rice. 2) Many improvements in convenience were carried out since early years, such as adding timer, function of various cooking, that of keeping heat in rice. 3) Improvements in taste were started from tightening cover lock to prevent leakage of steam and lowering of its pressure. In later years, the mechanisms of heating were improved, but it didn't go far enough.
