A thin-film solar cell module of a light transmission type includes a light-transmissive substrate; a front electrode layer; a rear electrode layer, and a photovoltaic conversion layer. The rear electrode layer, front electrode layer, and photovoltaic conversion layer are sequentially laminated on the light-transmissive substrate. A heat retention member covers the rear electrode layer, and a sealing layer is provided for sealing the rear electrode layer. In certain embodiments, the heat retention member has a light absorptance of 40% or more within a near-infrared wavelength range of 1,500 to 2,000 nm.