The present heat-resistant tungsten alloy has a first phase containing W as a major component, a second phase having a carbonitride of at least one element of Ti, Zr and Hf and containing the carbonitride as a major component when W is removed, and a third phase having a carbide of at least one element of group 5A elements in the periodic table and containing the carbide as a major component when W is removed, the heat-resistant tungsten alloy having a Vickers hardness of 550 Hv or more at a room temperature, a displacement of 1 mm or more when leading to fracture, as determined in a three point bending test at 1200° C., and a 0.2% proof stress of 900 MPa or more, as determined in the three point bending test at 1200° C.