The present invention discloses a compact converter including a compact casing having an air inlet defined thereon, a printed circuit board supported within the compact casing at a position between a top and a bottom wall of the compact casing to form an upper air channel between the printed circuit board and the top wall of the compact casing and a lower air channel between the printed circuit board and the bottom wall of the compact casing, wherein the lower air channel is communicating with the upper channel; a cooling fan is electrically mounted on the printed circuit board at a position aligning with the air inlet for drawing exterior air through the air inlet to the lower air channel to create an air circulation between the lower air channel and the upper air channel, so as to cool down the printed circuit board.