When forming valve seat coats at opening portions (16a1 to 16a8) of intake ports (16) provided at a cylinder block mounting surface (12a) of a semimanufactured cylinder head (3), the nozzle of a cold spray apparatus moves along a nozzle movement path for air intake (Inp1) that is set between any two of the plurality of opening portions (16a1 to 16a8), while continuing to spray a raw material powder. When forming valve seat coats at opening portions (17a1 to 17a8) of exhaust ports (17), the nozzle moves along a nozzle movement path for air exhaust (Enp1) that is set between any two of the plurality of opening portions (17a1 to 17a8), while continuing to spray the raw material powder.