“…At the first moment, we establish a result on the existence and uniqueness of solutions of (1.1) in the function space L 2 (a, b), whose proof is based on the Banach Fixed Point Theorem. Some authors established criteria for the existence of solutions of nonlinear functional integral equation in Banach spaces by using basic fixed point theorems, such as [8,10,11,12,13], for instance. However, the conditions about existence and uniqueness were used depending on the Carathéodorytype conditions of the kernel, which are not required in this work.…”