A cooling structure of a heating element includes: the heating element having at least one cooling surface from which a plurality of pin fins project; a heat receiving plate which has a shape complying with the cooling surface and in which holes are formed at positions facing each pin fin, each pin fin being movably inserted into the holes; a cooler which has a pair of clamping members that sandwich therebetween the heating element and the heat receiving plate while pressing the heating element and the heat receiving plate, and which cools the heat receiving plate; and a space securing part which is provided on the heat receiving plate and suppresses a distance between the pair of clamping members so as not to apply a pressing force by the clamping members to the heating element.