In developing new personal electronic products, the development time has shortened to a few months due to high competition in the market. Now it has become very hard to meet the time to market by evaluating products by making physical prototypes. To overcome this problem, we propose an immersive modeling system (IMMS) that enables us to interact with a digital product model in the augmented virtual environment using a multi-modal interface. The IMMS allows the user to evaluate the product model realistically using visual, auditory, and tactile/force senses. The architecture and main modules of the system are described in detail. The integration problems encountered during the development of the test bed are discussed. Application examples to personal electronic products are also included.