A substrate for mounting an electronic part and a method for producing the same, which allows a conductive pin to be inserted and secured in a through hole without exerting any damage thereto. The substrate for mounting an electronic part is formed of a through hole piercing an insulating substrate and a conductive pin with its head inserted into the through hole. The head of the conductive pin is provided with a plurality of projections to its side wall, each projecting radially in 4 or more directions. Those projections form a plurality of pairs, each of which is extending in an opposite direction from an axial center of the head. Those projection pairs include a primary projection pair having a largest length and a secondary projection pair having a second largest length. The length of the primary projection pair is equal to or more than an inside diameter of the through hole. The length of the secondary projection pair is less than the inside diameter of the through hole.