This paper examines the impact of new technology on plant-level productivity in the Japanese steel industry during the 1950's and 1960's. We estimate the production function, considering the differences in technology between the refining furnaces owned by a plant. We find that a more productive plant was likely to adopt the new technology and that the adoption would be expected to occur immediately following the peak of the productivity level achieved with the old technology. The adoption of the new technology primarily accounted not only for the industry's productivity slowdown but also for the industry's remarkable growth.