Design and construction of organic Field Effect Transistor (OFET) using (Copper-phthalocyanine) (CuPc) as a metal organic semiconductor with different thicknesses of Silicon dioxide (SiO2) as a gate insulator using Pulsed Laser Deposition technique (PLD). CuPc OFET used in memory devices including radio frequency identification cards (RFIDs), smart tags, electronic newspapers, and flexible displays . Thin films of (CuPc) were deposited on Silicon wafer (n-type) substrates with pre-deposited of SiO2 with different thickness of (100,200,300)nm. Three Aluminum electrodes (drain, source, gate) deposited on the device with thickness of (200)nm using thermal evaporation technique. The constructed transistor is p-channel type with channel length L=0.25mm and channel width W=4.7mm.  Output and Transfer characteristics of OFET devices are studied. The results show CuPc OFETs characteristics are in agreement with the theoretical results. The electrical properties for the constructed device enhanced with decreases thickness of the insulator layer. The switching ratio was about 2.6×102.