Provided is a hot-forged TiAl-based alloy of the present invention containing 40 to 45 atom % of Al and additive elements in the following composition ratio (A) or (B), and the balance Ti with inevitable impurities: (A) Nb: 7 to 9 atom %, Cr: 0.4 to 4.0 atom %, Si: 0.3 to 1.0 atom %, and C: 0.3 to 1.0 atom %; and (B) at least one of Cr: 0.1 to 2.0 atom %, Mo: 0.1 to 2.0 atom %, Mn: 0.1 to 4.0 atom %, Nb: 0.1 to 8.0 atom %, and V: 0.1 to 8.0 atom %. The TiAl-based alloy is characterized by having a fine structure of densely arranged lamella grains that are laminated alternately with a Ti3Al phase (α2-phase) and a TiAl phase (γ-phase) and have an average grain size of 1 to 200 μm.