This paper presents the investigation on the demand of domestic companies for reliability. For persons undertaking reliability tasks of 224 companies, the questionnaire study is made to investigate the importance and necessity of reliability, needs and priorities of reliability manuals, and the appropriate scheme to propagate them by internet and telephone. By analyzing the responses according to fields of industry, types of manufacturing, numbers of employees, and total sales, we obtained the useful informations for developing and propagating reliability manuals.