Pentacene thin-film transistors using polymethil methacrylate as a gate dielectric have been fabricated. The maximum temperature throughout the whole process was 170 /spl deg/C. The organic devices show satisfactory p-type electrical characteristics with on/off ratios exceeding 10/sup 3/ for V/sub GS/ ranging from -30 to 30 V. The field-effect mobility and threshold voltage were around 0.01 cm/sup 2//V/spl middot/s and -14 V respectively.