A set of problems are discussed, which must be studied before the public relations are dealt with. Firstly, the trade-off between energy and health must be considered. Although the probability of death caused by atomic accidents is very small (one three hundred millionth a year), many peoples hate atomic power and oppose to the construction of nuclear power plants. Four reasons for this are considered: (1) social diffusion of innovation, (2) nuclear allergy, (3) shortage of the conception of risk-benefit, and (4) heterogeneity of the public. According to the investigation of the relationship between electric power and livelihood, carried out by the policyand science research institute in Tokyo, the highly subjective decision for the acceptance of atomic power is independent of the objective knowledge on atomic power.