Due to the rise in demand for portable electronic device, low power and low voltage circuit design is extremely important for the appliances like computers, laptops, mobile phones and etc. Low power dissipation results in longer battery life and better integration density. This can be achieved by designing a modified low voltage op amp. The design of low voltage op amp in this paper is the combination of several low voltage analog cells. The modified low power op amp in this paper is built based on low voltage basic op amp. In this paper, the design objective is to achieve certain criteria such as supply voltage as low as 1 V, high gain more than 40 dB, low power consumption and high bandwidth. The use of FGMOS would increase the operating range of op amp through programming the threshold voltage of the FGMOS. This project is simulated using Silvaco Gateway and Expert.