PURPOSE: To enable the electrical connection between two printed boards assuredly by a method wherein a connecting wire is inserted into through-holes bored in circuit formed parts of both the boards respectively and connected with a circuit section around the through-hole through which the connecting wire passes with solder.

CONSTITUTION: One end of a connecting wire is inserted into a first through-hold 12 provided to a circuit non-formed part of a first printed board 1 and a through-hole 14 provided to a circuit formed part of a second printed board 2 and electrically connected to the circuit of the board 2 through a soldered joint 17. And, the other end of the connecting wire is inserted into a second through-hole 13 provided to a circuit formed part of the first printed board 1 and electrically connected to the circuit of the first printed board 1 through a soldering joint 18. By these processes, the circuits of both the boards 1 and 2 are electrically connected with each other through the connecting wire 15.