To obtain a stable technique for recovering titanium by which aluminum bonded to titanium can more easily be dissolved away with acid, the control of the reaction is easy, complicated equipment is not needed, and the surface of titanium after pickling stay neat.

At the time of recovering titanium from a titanium material bonded with aluminum, aluminum is preferentially dissolved away with a mixed aq.soln. of hydrofluoric acid and hydrogen peroxide or a mixed aq.soln. obtd. by adding this with inorganic acid other than hydrofluoric acid, and titanium is allowed to remain. The mixed aq.soln. contg. 0.1 to 20% hydrofluoric acid and 10 to 80% hydrogen peroxide is desirable.