A solar receiver is disposed on a top portion of a tower provided upright on the ground for heating a compressible working fluid by means of heat converted from sunlight collected by heliostats disposed on the ground, to raise the temperature of the compressible working fluid. The solar receiver has modules disposed back-to-back, and each of which includes a casing having a bottom plate to be fixed to the top-portion upper surface of the tower. A heat-transfer-tube unit is accommodated in the casing and includes heat transfer tubes. A sunlight inlet port having a circular shape in front view or an elliptical shape in front view is provided at the center portion of a plate-like member whose lower end is connected to an outer circumferential end of the bottom plate to constitute the casing and that extends obliquely upward from the outer circumferential end.