Method of forming sprayed film on the inner surface of a bore

A sprayed film forming method and apparatus in which the thickness of the sprayed film in a predetermined region is increased so as to unify the entire thickness. A sprayed film is formed at a cylinder bore inner surface while a spraying gun is moved in an axial direction during rotation inside the bore. Air inside the bore is sucked out to prevent foreign material from being caught in the sprayed film. The flow rate inside the bore tends to become higher at an axial end on a suction side, resulting in a thinned region. The supply speed of a wire serving as a spraying material to the spraying gun or the number of sprays in this region is higher than those at other portions. The thickness at the axial end of the bore is made equal while suppressing an increase in working time and spraying material used.