An integrated app store device according to the present invention includes an authentication server performing registration and authentication on a client terminal, a content managing server performing one of registration, search, and download of an application, a web application server providing a web front for a user, and an interworking server providing an open API (Application Programming Interface) for an external app store to access. Accordingly, functions of an app store are defined in the form of a standard-based common interface (Open API) and various terminals and platform environments are supported, thus providing an open-type app store model that may be efficiently expanded even when the type of user terminal and type of service or business environment are varied.