A coating nozzle includes an elongate nozzle body having a coating solution reservoir defined longitudinally therein for being supplied with a coating solution from an external coating solution supply. The elongate nozzle body also has a coating solution holder defined therein and opening away from the coating solution reservoir, for holding a coating solution against falling off as droplets under surface tension of the coating solution. A plurality of passages are defined in the elongate nozzle body and held in communication with the coating solution reservoir and the coating solution holder, for supplying the coating solution from the coating solution reservoir to the coating solution holder. The arrangement of the reservoir, the solution holder and the passages in the elongate nozzle body assures that a uniform layer of coating solution is deposited by the nozzle on a surface of a planar substrate.