An arm material for an upper arm or a lower arm is provided which constitutes a double wishbone suspension or the like of an automobile and which has a flat, hollow, closed cross-sectional shape and enables further decreases in size, decreases in weight, and increases in strength.An arm material for an automobile suspension has a body made from a parts material made by metal. The parts material made by metal has a flat, hollow, closed cross-sectional shape having a pair of opposing long sides and is formed from a single member in its lengthwise direction. The body has at least a first bent portion which is bent in a plane roughly parallel to the pair of long sides.