The secondary electron coefficient δ of a 98% Cu-2% Be alloy was measured as a function of the electron accelerating voltage. The alloy as processed by the manufacturers had a maximum value of δ, equal to 1.75 at an accelerating voltage of 330 V, decreasing to 1.4 at 290 V in the presence of Silicone D.C. 704 vapour. The presence of a 1400 A thick film of polymerized Silicone D.C. 704 (hydrated by exposure to air) on the Cu-Be surface reduced the value of δmax to 1.05 at 270 V. The polymer film was removed by sputtering in an argon atmosphere and δmax rose to 2.05 at 340 V. The values of δ measured here are low compared with those obtained in a multiplier and this is ascribed to incorrect oxidation of the target surface.