The detailed structure of an electrochemically produced poly(phenol) film is investigated in situ by neutron reflection. The surface density of the polymer is measured, and its thickness is determined accurately from fits to reflectivity data. From contrast variation measurements it is seen that there is penetration of solvent into the growing film, but only in the topmost part. Kinetic measurements are made on the deposition process for the polymer film. The potential of the technique for studies of protein adsorption is discussed.