An ink jet recording apparatus including an ink jet recording head which ejects a droplet of an ink toward a recording medium, a driver circuit device which applies an electric voltage to the ink jet recording head so that the ink jet recording head ejects the droplet of the ink toward the recording medium, a carriage on which the ink jet recording head and the driver circuit device are mounted, and a first heat sink and a second heat sink which are mounted on the carriage such that the first and second heat sinks cooperate with each other to sandwich the driver circuit device and define an inner space.