Abstract: Herein disclosed is a heat pipe type heat exchanger which comprises: a container for containing a first heating medium therein or causing the same to flow therethrough; at least one heat pipe extending liquid-tight with a substantially horizontal axis through the container; and a tube extending gas-tight and axially through the heat pipe for causing a second heating medium to flow therethrough, whereby the heat exchange is effected between the first and second heating mediums through the walls of the heat pipe and the tube. In case a plurality of heat pipes are provided, the individual tubes extending axially through the corresponding heat pipes are connected at their ends to each other by means of bends such that they make a zigzag or meandering piping. This retains a wide heat exchanging area.