Provided is a pipe joining body in which a wire rod and a tubular member are joined. The wire rod includes a concave portion formed by plastically deforming a part of an outer periphery of the wire rod. The tubular member includes a deformed portion that is formed so as to enter the concave portion by inserting the wire rod into the tubular member and by pressing a portion of the tubular member covering the concave portion toward the concave portion to plastically deform the portion. A maximum displacement amount of the tubular member when the deformed portion is formed is not larger than a maximum displacement amount of the wire rod by the plastic deformation when the concave portion is formed. The concave portion is formed by bringing a mold having a convex surface into contact with the part of the outer periphery of the wire rod to press.