A brain probe includes: a core probe made from a metal and n electrode plates attached so as to cover an entire side surface circumference of the core probe and forming n side planes providing an n-angular cross section (n is an integer equal to or greater than 3). Each of the electrode plates is manufactured by a LSI manufacturing process, and provided with at least one electrode and a lead-out wiring extending in a longitudinal direction of a side plane from each of the at least one electrode.