A heat transfer thruster by which performance can be enhanced by realizing optimal temperature distribution for heating propellant without complicating the structure. In the heat transfer thruster, propellant flows through two pipes (102, 104) into the thruster body (106) thence flows through a channel (110) formed in the thruster body (106) to the nozzle side while being heated from the thruster body (106) which is heated by a heat source, and reaches a plenum chamber (114) in front of a nozzle before being injected from a propellant outlet along the outer wall (126) of a plug nozzle (112). Heat from the heat source is transmitted directly to the nozzle through the inner wall (128) of the plug nozzle (112). In other words, the hollow section (118) of the plug nozzle (112) functions as a heating section for the nozzle.