PURPOSE: To provide an insulation wall structure which is applicable to a wooden house and excellent in terms of insulation properties and air tightness.

CONSTITUTION: A first layer of furring 3 is installed at a specified span and runs straightly between the sides of a wooden axial part 1 and a first layer of insulation sheet is fitted between the opposed first layer of furring 3 as well. A sheet is extended all over the outside surface of the wooden axial part 1 and the outside surface of the first insulation sheet 2. A second layer of furring 3 is installed at a specified span along the wooden axial part 1 while a second layer of insulation sheet 2 is fitted between the opposed second layer furring 3.