A solar collector for a solar heat boiler, comprising: a plurality of heat transfer pipes inside which a fluid to be heated flows; cylindrical headers (1, 3, 5) which are disposed in opposite positions and connected to opposite end portions of the heat transfer pipes respectively; and a planar solar heat collection portion which is formed out of the heat transfer pipes and membrane bars fixing adjacent ones of the heat transfer pipes to each other; wherein: the cylindrical headers include an inlet header into which the fluid to be heated flows, an intermediate header which is disposed in a position opposed to the inlet header with interposition of the heat transfer pipes, and two outlet headers which are provided to extend on opposite end sides of the inlet header and through which the fluid introduced from the intermediate header through the heat transfer pipes can be discharged to the outside; and the planar solar heat collection portion includes a first heat collection subportion which is formed out of a group of the heat transfer pipes connected between the inlet header and the intermediate header and the membrane bars for the group of the heat transfer pipes so as to form a center region of the solar heat collection portion extending in an axis direction of each heat transfer pipe, and second heat collection subportions which are formed out of groups of the heat transfer pipes connected between the intermediate header and the two outlet headers and the membrane bars for the groups of the heat transfer pipes so as to be formed on opposite sides of the first heat collection subportion respectively; wherein a shielding plate is disposed between the first heat collection subportion and the second heat collection subportion; and the shielding plate is attached to one of the heat transfer pipes by welding and is not fixed by welding to the other heat transfer pipe but is in contact therewith. the cylindrical headers include an inlet header into which the fluid to be heated flows, an intermediate header which is disposed in a position opposed to the inlet header with interposition of the heat transfer pipes, and two outlet headers which are provided to extend on opposite end sides of the inlet header and through which the fluid introduced from the intermediate header through the heat transfer pipes can be discharged to the outside; and the planar solar heat collection portion includes a first heat collection subportion which is formed out of a group of the heat transfer pipes connected between the inlet header and the intermediate header and the membrane bars for the group of the heat transfer pipes so as to form a center region of the solar heat collection portion extending in an axis direction of each heat transfer pipe, and second heat collection subportions which are formed out of groups of the heat transfer pipes connected between the intermediate header and the two outlet headers and the membrane bars for the groups of the heat transfer pipes so as to be formed on opposite sides of the first heat collection subportion respectively; wherein a shielding plate is disposed between the first heat collection subportion and the second heat collection subportion; and the shielding plate is attached to one of the heat transfer pipes by welding and is not fixed by welding to the other heat transfer pipe but is in contact therewith.