[en] While considering the Chernobyl Forum report in September 2005 as a starting point, the author thought about the 'number of the dead' caused by the Chernobyl accident with a simple diagram 'nuclear accident → radioactive contamination → radiation exposure effect' in mind. In the Forum, as the summary of accident impact study for 20 years, it concluded that 'the number of the dead due to the radiation accidents will be 4000 including future death from cancer'. The statement of 'about 60 of the dead so far' in the Forum is the number that was confirmed by the Forum as that the cause was radiation exposure, not including dead people not confirmed by the Forum. It is said that the number of accident treatment workers mobilized in 1986 (liquidators) was from 600 to 800 thousand, of which about 200 thousand workers who worked during 1986 and 1987 were deemed to have received large exposure. Compared with Ukraine and Belarus, proper follow-up surveys have been conducted in Russia. When looking at the ratio of dead number against that predicted from the demographics of Russians of the same age (Standard Mortality Ratio [SMR]), although excessive death was not recognized, it increased with aging. In estimating the number of cancer deaths, 4000 cases in the Forum are the lowest among the reports so far. Greenpeace has issued a value of more than 20 times, 93,000 cases. If the fatalities of liquidators (6,000 people so far and ultimately 30,000 people) are added, the death toll from radiation exposure due to the Chernobyl accident eventually amounts to 50,000 to 90,000 people. (A.O.)