Functional Near-Infrared Spectroscopy (fNIRS) is an instrumentation method that performs both the cerebral hemodynamic, by using near-infrared light, and continuous non-invasive analysis of the oxygen level inside the tissue. Furthermore, this approach provides additional physiological parameters that can be correlated with cerebral activities by measuring the levels of oxygenation. In comparison to other techniques, fNIRS is well known for being low-cost, compact and presenting satisfactory spatial and temporal resolutions. Currently, hot topics in neuroscience are related to the studies of visual area, somatosensory, auditory, motor, language, cognitive and psychiatric. Such studies, generally, focus on cerebral physiology and biochemistry during certain stimulus or conditions imposed on the patient, in addition to their impact on cerebral hemodynamics. This work proposes a multichannel fNIRS system that implements the acquisition, control and digital signal processing in a portable platform. Such implementation of this system aims to jointly work with a Brain Computer Interface (BCI), where research about cerebral cortex are intended of being conducted.