In this study, air flow through a microchannel between two parallel plates of height ranging from 100 to 710 mu m was investigated experimentally. Each channel was made of Plexiglas and had a large cross-sectional aspect ratio to supply the microplaneduct geometry. The flow rate and pressure drop across the microchannel were measured at steady state to obtain the friction factor. The Reynolds number ranged from 30 to 2300. The experimental friction factor values were found in good agreement with an existing analytical solution for an incompressible, fully developed, laminar flow under no-slip boundary conditions.