A surface-treated copper foil, wherein a surface-treated layer is formed on a copper foil, satisfying at least one of the following (A) to (I), and when the surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the proportion of the white portions on the surface, on the copper foil removal side, of the resin substrate is 55 to 68%,
- (A) the number density of the particles on the surface of the surface-treated layer is 3.8 to 430 particles/μm2, and the proportion of the area corresponding to the particles of the surface of the surface-treated layer is 0.1 to 0.85,
- (B) the average diameter of the particles on the surface of the surface-treated layer is 0.03 to 0.28 μm, and the number density of the particles on the surface of the surface-treated layer is 3.8 to 430 particles/μm2,
- (C) the number density of the particles on the surface of the surface-treated layer is 3.8 to 430 particles/μm2,
- (D) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the average length of white portions on the surface, on the copper foil removal side, of the resin substrate is 0.07 to 0.23 μm,
- (E) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the maximum length of the white portions on the surface, on the copper foil removal side, of the resin substrate is 0.704 to 0.88 μm,
- (F) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the average length of the largest 10 white portions on the surface, on the copper foil removal side, of the resin substrate is 0.15 to 0.457 μm,
- (G) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the average length of black portions on the surface, on the copper foil removal side, of the resin substrate is 0.035 to 0.20 μm,
- (H) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the maximum length of the black portions on the surface, on the copper foil removal side, of the resin substrate is 0.180 to 0.605 μm, or
- (I) when a surface-treated copper foil is bonded, via the surface-treated layer side of the surface-treated copper foil, to a resin substrate and the surface-treated copper foil is removed, the average length of the largest 10 black portions on the surface, on the copper foil removal side, of the resin substrate is 0.06 to 0.335 μm.