The cap for attaching EEG electrodes is made of silicone tubes connected by movable clamps into a frame in the shape of the head. The cap is designed for use with cup electrodes MCScap-StTC/StNT, which have a special notch for attaching directly to the cap tube. The design of the cap provides the ability to continuously change the distance between each pair of electrodes, as well as free access to the electrode, including from the side of the contact surface. The tubes of the cap shell can be replaced if necessary.