A heating element cooling apparatus which is capable of improving the cooling efficiency without greatly increasing the overall weight thereof. A heat sink 2 for the heating element cooling apparatus is equipped with an air fan 1. A heat conducting element 3 having higher heat conductivity than a base 2a of the heat sink 2 is conductivity attached to the base 2a. Plural radiation fins 6 are mounted on an extended portion 3c of the heat conducting element 3 which extends exceeding the base 2a. The heat generated by a heating element 4, which is heat-conductively attached on the heat conducting element 3, is outwardly conducted toward the peripheral portion of the heat sink through the heat conducting element 3 and radiated from the radiation fins 2b, resulting in increasing the radiation efficiency.