To inexpensively provide a ventilation construction method for an exterior wall, which can be easily executed, which can construct an exterior wall having an exterior wall surface layer excellent in endurance such as resistance to cracks etc. and ensuring high ventilation performance and a dew-proofing function.

This method for constructing an exterior wall, to which a ventilation system is applied, comprises: a step of forming a wooden structural skeleton by using vertical and horizontal structural members; a step of forming a bed structure by providing a heat insulating material inside the structural skeleton and sticking a plate material on the heat insulating material; a step of sticking an air-permeable sheet on the outdoor-side surface of the bed structure; a step of sticking a waterproof sheet on the air-permeable sheet; a step of providing a lath net on the waterproof sheet; and a step of providing a mortar layer with a predetermined thickness on the lath net. The above steps are performed in this order, so that the exterior wall can be constructed.