To reduce heat dissipation from a bottom plate and side plates of a case of a solar heat collector, and to improve heat collection efficiency over a wide range from low-temperature collected heat to high-temperature collected heat.

The solar heat collector is configured in such a manner that a bottom plate 1a and side plates 1b of a case 1 which has an open upper face is composed of a vacuum insulating material 5 which is formed by covering a core material 6 which is formed by compressing a heating insulating material and has heat insulation properties and a gap with an outer skin 7 and creating a vacuum in a space formed of an outer skin. The outer skin is formed by welding peripheral edges of two metallic plates disposed so as to face each other across the core material. A plurality of linear grooves 21c with any one section of triangular, arcuate and sine half-wave shapes are formed in the metallic plates, and the two metallic plates are disposed across the core material with protrusions of the linear grooves facing each other.