PURPOSE: To make a fiber-reinforced metal exhibit a heat treating effect and to improve its strength, etc.

CONSTITUTION: This fiber-reinforced metal is formed by using an Si-containing aluminum alloy Ala as matrix metal and reinforcing it with whiskers A as a reinforcement material consisting of aluminoborate, and Na or Na compound is allowed to adhere to the whiskers A to form an Na-attached reinforcement material. By using this Na-attached reinforcement material and eluting Na into the aluminum alloy Ala, the peripheries of the whiskers A are coated with eutectic Si phases forming during solidification and crystallized substances C of intermetallic compound, and the whiskers A are dispersed and incorporated, in the state where the reaction between Si and whiskers A is inhibited, into the aluminum alloy Ala.