In a solar cell roof structure, a photovoltaic power generating apparatus, a building and a method of construction of a solar cell roof, in which a solar cell module is provided above a roof base of a building, an electrical wire for the solar cell module is provided in a space between the solar cell module and the roof base, and the electrical wire extends into a space at the back of the roof base through a through hole provided in the roof base. A base sealing member on the roof base is provided for covering the through hole and an exit is provided in the base sealing member through which the electrical wire extends into the space between the solar cell module and the roof base at a portion of the base sealing member other than a portion just over the through hole of the base sealing member. The base sealing member can include a heat-resisting or fire resistive material on the roof base for covering the through hole.