A carriage arm assembly for swingably supporting a magnetic head which includes a slider, a suspension carrying the slider, a carriage arm to which the suspension is attached, and a body section. The body section includes first and second arm members extending substantially in parallel with a swinging plane of the carriage arm, and a fixing portion provided at a distal end of the carriage arm for mounting the suspension thereon. Each of the first and second arm members have narrow sections in a distal end area and a base end area thereof, wherein a width of the narrow sections in a swinging direction is smaller than a width of an intermediate area of the first and second arm members.