The design of the fuel cell plays a major role in determining their cost. It is not only the cost of materials that increases the cost of the fuel cell, but also the manufacturing techniques and the need for skilled technicians for assembling and testing the fuel cell. The work presented in this paper is part of a research work aims to design and manufacture a proton exchange membrane (PEM) modular fuel cell of 100 W output at low cost using conventional materials and production techniques, then testing the fuel cell to validate its performance. This paper will be dealing only with the design of a modular fuel cell that can be mass produced and used to set up a larger fuel cell stack for stationary applications (6 kW) which is capable of powering a medium sized household. The design for 100 W fuel cell module will include the calculations for the main dimensions of the fuel cell components, mass flow rate of reactants, water production, heat output, heat transfer and the cooling system. This work is intended to facilitate material and process selection prior to manufacturing alternatives prior to capital investment for wide-scale production. The authors believe that the paper would lead to a stimulating discussion.