To efficiently perform ventilation even under the condition in which a heat receiving quantity from the sun is large and the ventilation efficiency is lowered, in a heat insulated ventilated roof construction providing a ventilation space between a sheathing roof board and roof tiles so as to enable a roof ridge to be ventilated.

A backing sheet 2 having radiation property is laid on the surface of a roof backing material 1, a spacer material 3 is arranged on the surface of the backing sheet 2, and a heat insulation panel 4 is laid on the spacer material 3 so as to cover the whole face of a roof and form a ventilation space S from the edge of the eaves toward the ridge. Roof tiles are roofed on the heat insulation panel 4, a ventilation ridge 6 communicated to the ventilation space S is provided on the ridge part, and a ventilating fan is provided in the ventilation ridge 6.