The friction factors for microchannels of 200 mu mX200 mu m and 500 mu mX200 mu m were obtained by measuring the pressure drops in the channels. The measured values were in a good agreement with ones predicted theoretically for Reynolds number, Re ranging from 5 to 100. The laminar flow profiles measured with polystyrene microbeads at a half of the channel depth also agreed well with the theoretical profiles for Re = 0.0238 and 0.0369.