In relation to a rocker arm obtained by applying cold forging to a blank made from a metal wire rod, cold forging is applied to a blank obtained by cutting a metal wire rod to a predetermined length to make a second intermediate blank 34b having a pair of side wall sections 2a and a base 39 which connects the two side walls 2a at one of their respective widthwise edges. Punching is applied to the base 39 of this second intermediate blank 34b to form a first and a second connection sections. In the case where it is assumed that a roller 35 is arranged at a position corresponding to an arrangement position of the roller 35 of the rocker arm to be obtained, on the inside of the second intermediate blank 34b which is to be subjected to punch processing, the roller 35 and the base 39 do not interfere with each other. As a result, performance improvement of an engine fitted with this rocker arm is obtained.