A heat spreader for cooling an electronic component includes a lower plate defining a chamber, an upper plate fixed on the lower plate to seal the chamber, a first wick layer and a second wick layer sandwiched between the lower plate and the upper plate, and a working liquid contained in the chamber. The first wick layer and the second wick layer respectively define a plurality of apertures, which include right-angled triangle, acute-angled triangle, and rhomboid apertures communicating with each other for containing the working liquid therein.