In an embedded apparatus including a Web server function and a plug and play function which enables and disables an operation of an option application by a detachable recording medium recording the option application while the embedded apparatus is operating, an access executing part executes an access to parameters of the option application in response to an access request, a monitoring part monitors an existence of the option application, and an acceptance rejecting part rejects an acceptance of an access request and disabling the access executing part to access the option application when the monitoring part determines that the option application does not exist when the access request is received.