PURPOSE: To omit a cold compacting process and to improve the productivity, at the time of heating Al alloy powder and directly subjecting it to hot forming to obtain a green compact, by rapidly heating the Al alloy powder at a specified rate by hot air.

CONSTITUTION: Al alloy powder is rapidly heated at ≥50°C/min rate by hot air and is subjected to hot forming. Since the Al alloy powder is rapidly heated at ≥50°C/min rate by hot air, the heating time may be short, and an oxidized film and a hydroxidized film are hard to form on the surface of the powder. Thus, it can be hot-formed into a desired shape without executing heating in an inert gas atmosphere. Moreover, since the heated powder is directly used for hot forming such as hot forging and extruding, a cold compacting process can be omitted, and the productivity is made excellent.