To provide a small radio apparatus capable of improving antenna characteristics, preventing electrostatic discharge damage, and improving mounting efficiency of components, a printed circuit board of the small radio apparatus, and a method of mounting the components of the small radio apparatus.

A copper foil pattern 102 of the printed circuit board 100 in which components such as an external interface connector 6 or the like covered with a metal plate are mounted at a lower part of the antenna 1 or the like, and a copper foil pattern 101 of the printed circuit board 100 constituted as a reference ground of electric circuit components 2-5 and the antenna 1 of the device body are electrically divided, and mutually connected by an inductance element 7 being open in a desired radio band. The inductance element 7 suppresses the occurrence of capacitive impedance between the components and the antenna in radio frequencies so as to prevent the antenna characteristics from being deteriorated. Further, the common reference potential upon operation can be secured by the inductance element 7. Furthermore, static electricity impressed on the components is released through the inductance element 7, preventing the electrostatic discharge damage of electric components.