To improve workability in outside construction by using an air-permeable and heat-insulating composite panel provided with a heat-insulating layer and an air-permeable layer to rationalize covering for heat insulation and formation of an air-permeable layer in an outside heat insulation method of a wooden building.

Linear grooves G for air permeation and thick parts 1C for layer fitting are alternately and vertically arranged on a layer fitting surface 1S of a heat insulation layer 1B of a foamed plastic heat insulation material. An exterior underlayer material 1A of a formed thin rigid plate is laid and fitted to the layer fitting surface 1S in an integrating manner to obtain the air-permeable and heat-insulating composite panel 1. A lower end of the panel 1 is supported by a panel receiving metal piece 7 fixed to a foundation 14C, and is held in a manner that the air can enter the group of the linear grooves G. The panel 1 is fixed to a wooden skeleton WF so that it may serve as an exterior wall. The draft rising air current (a) goes through the vertical linear grooves G in the panel 1 from the lower end to the upper end of the exterior wall.