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 (30, 40) including a plurality of dual-axial solar tracking type reflection mirrors (31, 41); 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 (30, 40) 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 (31, 41) 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 (30, 40) 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 (30, 40) 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 (30, 40); 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 (30, 40) including a plurality of dual-axial solar tracking type reflection mirrors (31, 41); 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 (30, 40) 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 (31, 41) 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 (30, 40) 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 (30, 40) 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 (30, 40); 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.