A photovoltaic module installation roof renewal method for installing a photovoltaic module , by using a portable roll forming machine , on a roof of a building constructed with a roof sheet having repetitively formed crests and troughs , the method comprising the steps of: interposing a heat insulator at the troughs of the roof sheet ; producing a photovoltaic module installation roof panel in a length corresponding to a length of the roof at a roof renewal site by using the portable roll forming machine and transporting the photovoltaic module installation roof panel onto the roof sheet ; installing the photovoltaic module installation roof panel on the roof sheet at which the heat insulator is interposed; fastening a bracket for installing a photovoltaic module on the photovoltaic module installation roof panel ; and installing the photovoltaic module on the bracket ; wherein the photovoltaic module installation module roof panel includes: a panel main body having, at one end portion in a width direction, a fitting projecting bar with a concave groove on a top surface thereof along a longitudinal length and, at the other end portion in the width direction, an elastic clip to be installed over a fitting projecting bar of a neighboring photovoltaic module installation roof panel , so that the fitting projecting bar is elastically inserted into the elastic clip ; and a fitting rail inserted into the concave groove , wherein the elastic clip has a bracket fitting groove to be inserted into the fitting rail of the neighboring photovoltaic module installation roof panel , wherein the bracket is fitted to the bracket fitting groove . interposing a heat insulator at the troughs of the roof sheet ; producing a photovoltaic module installation roof panel in a length corresponding to a length of the roof at a roof renewal site by using the portable roll forming machine and transporting the photovoltaic module installation roof panel onto the roof sheet ; installing the photovoltaic module installation roof panel on the roof sheet at which the heat insulator is interposed; fastening a bracket for installing a photovoltaic module on the photovoltaic module installation roof panel ; and installing the photovoltaic module on the bracket ; wherein the photovoltaic module installation module roof panel includes: a panel main body having, at one end portion in a width direction, a fitting projecting bar with a concave groove on a top surface thereof along a longitudinal length and, at the other end portion in the width direction, an elastic clip to be installed over a fitting projecting bar of a neighboring photovoltaic module installation roof panel , so that the fitting projecting bar is elastically inserted into the elastic clip ; and a fitting rail inserted into the concave groove , wherein the elastic clip has a bracket fitting groove to be inserted into the fitting rail of the neighboring photovoltaic module installation roof panel , wherein the bracket is fitted to the bracket fitting groove . a panel main body having, at one end portion in a width direction, a fitting projecting bar with a concave groove on a top surface thereof along a longitudinal length and, at the other end portion in the width direction, an elastic clip to be installed over a fitting projecting bar of a neighboring photovoltaic module installation roof panel , so that the fitting projecting bar is elastically inserted into the elastic clip ; and a fitting rail inserted into the concave groove , wherein the elastic clip has a bracket fitting groove to be inserted into the fitting rail of the neighboring photovoltaic module installation roof panel , wherein the bracket is fitted to the bracket fitting groove . <EOS>