We devised an X-ray examination to detect early gastric cancer, especially small gastric cancer, during the period between 1996 and 1997. As a result, the rate of gastric cancer detection by mass screening was 0.50%; and the rate of early gastric cancer detection was 79%. 1. Characteristics of gastric cancer detected by mass screening: Characteristics of gastric cancer were depressive-type undifferentiated cancer less than 4.0 cm diameter in work-place screening and depressive-type differentiated cancer less than 4.0 cm in area screening; 2. gastric cancer less than 2.0 cm in diameter was 75 (68%) of the 110 cases (total detected gastric cancer). 2) We have to consider that gastric cancer differs by sex and age. 3) EMR accounted for 39 (35%) of the 110 cases in treatment. This method resulted in a higher gastric cancer detection rate and served to maintain QOL.