For a long time, fish residues and dead fish have been processed at the fish meal plant for production as livestock feed. However, due to the necessity of scaling up the plant in order to achieve a reasonable profit margin, unavoidable cost increases were incurred for apparatus, running costs and maintenance. Additionally, there were the problems of finding a location for the plant for the treatment of waste water and hazardous odours, as well as the additional expensive treatment apparatus connected with this. On account of these reasons, many plants have been forced to cease operation. As to the installation of smaller plant, this was found to be uneconomic due to the cost/performance ratio. With the Okadora system, we are able to offer a range of plant with a capacity of from 20kgs/hr to 20tons/day, thus reducing the cost by 1/2 ~ 1/10. Additionally, the operation is without emission of strong smells or waste water, making it pollution-free.