To provide an in-wall construction method using charcoal, which enables the charcoal with various effects to be easily and inexpensively charged into an in-wall space of a wall of an existing dwelling etc.
In this in-wall construction method using the charcoal, bamboo charcoal 7 is charged into the in-wall space 8 of the wall 3 which comprises an interior wall 4 facing a room 2 of the dwelling 1 and an exterior wall 5 facing the interior wall 4. This construction method comprises a hole drilling process wherein a first hole 9 and a second hole 10 are drilled into the interior wall 4, and a charcoal charging process wherein the bamboo charcoal 7 is charged into the in-wall space 8 through the first hole 9 and the second hole 10. The in-wall space 8 and the room 2 are ventilated through the first hole 9 and the second hole 10, which are drilled in the interior wall 4 in the hole drilling process.