This paper intends to clarify the development mechanism of an entrepreneur type of laying hen farming. This kind of form takes a different course from that of a family farm. With this in view, the author worked out a case study. The Aikeien Poultry Farms Co., with an amount of 450 thousands hens was taken up as a specimen among prominent entrepreneur type of laying hen farmings in the Kanto region. This company is composed of three independent farms tied together by father-son and brother relationships; it acquires scale merit by means of collective purchase of feed, information exchange, mutual security for credit, etc., although they are scattered within the range of a hundred kilometers around the capital. The company, at present, reached the stage of maturity after going through all the growing phases from its founding on. During these periods, the initial loaction was moved for reasons of manure pollution and diseases, and the company dispersed to suit better the sons independence. In the development mechanism of the entrepreneur type and the family farm type regarding laying hen farming the following differences are found. 1. The scale merit is realized by the enlargement of the internal economy in the company. 2. The way to expand internal economy is location changing from higher to cheaper price lands under the inflation. 3. The company is self-supporting (using no government funds). 4. Looking for upland crop areas in the suburbs, the company could systematize its production ancl succeeded in establishing a new type of laying hen farming.