This article deals with a new proteinic formed-in place membrane built on top of an alpha-alumina macroporous ceramic support (0.2 mu m SCT membrane). The initial proteinic deposit is obtained through tangential filtration of gelatin solutions. Then subsequent chemical and/or physical treatments are applied. In a first part of the study it is shown that by tanning (with formaldehyde) plus thermal drying of the gelatin layer low ultrafiltration performance may be reached. In the second part, the effect on membrane performance of the protein deposition conditions (concentration and pH of protein solution, velocity, pressure) is analyzed. From experimental results, it appears clearly that the best membrane so obtained has a cut-off point around 2 kDa and a flux as high as 101 h(-1) m(-2) under 200 kPa.