An organic n-type transistor, where both insulating and active layer were processed from solution, has been produced. As the active layer the C-60-derivative, [6,6]-phenyl C-61-butyric acid methyl ester (PCBM), was used. Its electron mobility was determined to be as high as mu(e) = 4.5 x 10(-3) cm(2) V-1 s(-1) when calcium drain/source contacts were used. If these contacts are formed from more air-stable metals, the device performance decreases.