A method of forming a fin forced stack inverter includes the following steps. A substrate including a first fin, a second fin and a third fin across a first active area along a first direction is provided, wherein the first fin, the second fin and the third fin are arranged side by side. A fin remove inside active process is performed to remove at least a part of the second fin in the first active area. A first gate is formed across the first fin and the third fin in the first active area along a second direction. The present invention also provides a 1-1 fin forced fin stack inverter formed by said method.