A wireless 64-channel ElectroCorticoGram (ECoG) recording implant named WIMAGINE(®) has been designed for clinical applications. This active implantable medical device is able to record ECoG on 64 electrodes with selectable gain and sampling frequency, with less than 0.7 µVRMS input referred noise in the [0.5 Hz - 300 Hz] band. It is powered remotely through an inductive link at 13.56 MHz, communicates wirelessly on the MICS band at 402-405 MHz with a custom designed base station connected to a PC and complies with the regulations applicable to class III AIMD. The design of the housing and the antenna have been optimized to ease the surgery and to take into account all the requirements of a clinical trial in particular patient safety and comfort. The main features of this WIMAGINE(®) implantable device and its architecture will be presented, as well as its performances and in vivo validations.