A solar heat collecting device comprising: a single-axial solar tracking type reflection mirror group including a plurality of single-axial solar tracking type reflection mirrors selected from Fresnel type reflection mirrors and trough type reflection mirrors; a dual-axial solar tracking type reflection mirror group including a plurality of dual-axial solar tracking type reflection mirrors ; a heat collecting unit that collects heat by receiving reflection light from the single-axial solar tracking type reflection mirror group and the dual-axial solar tracking type reflection mirror group to transfer the heat from a first end to a second end in a length direction of the unit ; characterised in that each dual-axial solar tracking type reflection mirror has a surface area of 5 to 20% of the surface area of one of the single-axial solar tracking type reflection mirrors ; the single-axial solar tracking type reflection mirror group is disposed so that long axes of the plural single-axial solar tracking type reflection mirrors face in a same direction; the dual-axial solar tracking type reflection mirror group is divided into a first dual-axial solar tracking type reflection mirror group and a second dual-axial solar tracking type reflection mirror group ; the first and second dual-axial solar tracking type reflection mirror groups are disposed side by side in a direction orthogonal to a long-axis direction of the plural single-axial solar tracking type reflection mirrors ; and the single-axial solar tracking type reflection mirror group is disposed sandwiched between the first and second dual-axial solar tracking type reflection mirror groups ; and the heat collecting unit is installed right above the single-axial solar tracking type reflector mirror group in the direction of the long axes of plural single-axial tracking type reflection mirrors . a single-axial solar tracking type reflection mirror group including a plurality of single-axial solar tracking type reflection mirrors selected from Fresnel type reflection mirrors and trough type reflection mirrors; a dual-axial solar tracking type reflection mirror group including a plurality of dual-axial solar tracking type reflection mirrors ; a heat collecting unit that collects heat by receiving reflection light from the single-axial solar tracking type reflection mirror group and the dual-axial solar tracking type reflection mirror group to transfer the heat from a first end to a second end in a length direction of the unit ; characterised in that each dual-axial solar tracking type reflection mirror has a surface area of 5 to 20% of the surface area of one of the single-axial solar tracking type reflection mirrors ; the single-axial solar tracking type reflection mirror group is disposed so that long axes of the plural single-axial solar tracking type reflection mirrors face in a same direction; the dual-axial solar tracking type reflection mirror group is divided into a first dual-axial solar tracking type reflection mirror group and a second dual-axial solar tracking type reflection mirror group ; the first and second dual-axial solar tracking type reflection mirror groups are disposed side by side in a direction orthogonal to a long-axis direction of the plural single-axial solar tracking type reflection mirrors ; and the single-axial solar tracking type reflection mirror group is disposed sandwiched between the first and second dual-axial solar tracking type reflection mirror groups ; and the heat collecting unit is installed right above the single-axial solar tracking type reflector mirror group in the direction of the long axes of plural single-axial tracking type reflection mirrors . <EOS>