The present invention provides an apparatus for lighting a brake lamp for a vehicle. The apparatus includes a brake pedal arm including a brake pedal at one end thereof, a pedal arm stop bracket integrally formed on the brake pedal arm at the upper side of the brake pedal arm, and a non-contacting switch that is separated from or comes in contact with the pedal arm stop bracket so as to be turned on or off depending on the operation of the brake pedal.