A skull cutting device for cutting a skull by means of laser comprises a body for emitting the laser introduced from a laser oscillator through an optical fiber from an exit opening arranged at a distal end thereof, a contact portion arranged in the body to determine the posture of the body such that a predetermined distance is set between a surface of the skull and the exit opening by touching the surface of the skull in a predetermined mode, a support bar of a predetermined length extending from the body toward the emitting direction of the laser while avoiding the optical path of the laser (R), and a light interception board arranged at a distal end of the support bar to block farther advance of the laser by interfering with the laser beam path.