Heat-dissipating circuit board, heat-dissipating member, and production method for heat-dissipating circuit board

A heat-dissipating circuit board comprising a metal material that is provided to be adjacent to one surface of an insulating layer and a conductive metal layer that is provided on the other surface of the insulating layer, wherein

• a material of the metal material is copper or a copper alloy or aluminum or an aluminum alloy, and the metal material has a sheet shape with a thickness of 0.2 mm or more and 20 mm or less, and
• the insulating layer is a metal oxide layer that is represented by a compositional formula:
• AlxOyTz,
• (where Al represents an aluminum atom, O represents an oxygen atom, T represents one atom or a plurality of atoms other than Al and O;
• x, y, and z denote a mass ratio, x+y+z=100, x is 30 or more and 60 or less, y is 40 or more and 70 or less, and z is 0 or more and 10 or less), and
• has a thickness of 0.2 μm or more and 30 μm or less, a volume resistivity of 1000 G Ω·cm or more, and a porosity of 10% or less.