This paper explores how a prototype of an IT appliance is manufactured through designing a housing of the appliance aesthetically, and designing the interface of its display. The aim of this study is to understand the role of prototype, and to clarify the problems and insufficient technology with which we should confront, and to investigate the efficient solutions to manufacture IT appliances well. The prototype manufacturing process presented here are to sketch the housings, to create clay models, to create 3D CAD models, to design interface of a display for an IT appliance, to manufacture functional mock-ups, and to examine the usability. An appliance to be developed is an artery pulse monitoring system named (APMOS). APMOS can measure blood pressure and the artery pulse, and let us know the condition for judging the possibility of arteriosclerosis. In this paper, we discuss in detail a manufacturing process from the concepts of the idea sketches to the usability test of the functional mock-up of APMOS.