A heavy load tire comprising: a tread portion; a pair of side wall portions continued to both ends of the tread portion; a pair of bead portions continued to the side wall portions; a carcass extended in a toroidal manner between the bead portions; and a belt layer arranged between the carcass and the tread portion, wherein: the belt layer has at least six belts laminated in a tire radial direction; a width of a third belt, which is arranged at a third position from an inner side in the tire radial direction among the belts, is set in range between 65% and 85% of a tire maximum width; a width of a fourth belt, which is arranged at a fourth position from the inner side in the tire radial direction among the belts, is set in range between 55% and 75% of the tire maximum width; each of the belts is formed of a metal cord-rubber composite formed by coating a plurality of metal cords with a rubber composition; characterized in that, the metal cord in each of the third belt and the fourth belt is formed such that N (nitrogen) atoms in a surface thereof is set in a range between 2 atom% and 60 atom% and a Cu/Zn ratio in the surface is set in a range between 1 and 4; and the rubber composition in each of the third belt and the fourth belt includes 1 part by mass to 15 parts by mass of silica and 0 parts by mass to 1 part by mass of cobalt-containing compound based on 100 parts by mass of a rubber component, wherein the N (nitrogen) atoms and the Cu/Zn ratio in a surface are measured using an X-ray photoelectron spectroscopy device under the measurement conditions set out below: X-ray source: Monochromatized Al-Kα ray Measurement region: 50 μmφ Measurement peak: C1s, O1s, N1s, P2p, Cu2p2/3, Zn2p2/3 Data treatment: Multipak Quantitation: quantitated from the obtained peak area by using relative sensibility coefficient method, * Cu/Zn is a ratio of quantitative values of Cu2p2/3 and Zn2p2/3. a tread portion; a pair of side wall portions continued to both ends of the tread portion; a pair of bead portions continued to the side wall portions; a carcass extended in a toroidal manner between the bead portions; and a belt layer arranged between the carcass and the tread portion, wherein: the belt layer has at least six belts laminated in a tire radial direction; a width of a third belt, which is arranged at a third position from an inner side in the tire radial direction among the belts, is set in range between 65% and 85% of a tire maximum width; a width of a fourth belt, which is arranged at a fourth position from the inner side in the tire radial direction among the belts, is set in range between 55% and 75% of the tire maximum width; each of the belts is formed of a metal cord-rubber composite formed by coating a plurality of metal cords with a rubber composition; characterized in that, the metal cord in each of the third belt and the fourth belt is formed such that N (nitrogen) atoms in a surface thereof is set in a range between 2 atom% and 60 atom% and a Cu/Zn ratio in the surface is set in a range between 1 and 4; and the rubber composition in each of the third belt and the fourth belt includes 1 part by mass to 15 parts by mass of silica and 0 parts by mass to 1 part by mass of cobalt-containing compound based on 100 parts by mass of a rubber component, wherein the N (nitrogen) atoms and the Cu/Zn ratio in a surface are measured using an X-ray photoelectron spectroscopy device under the measurement conditions set out below: X-ray source: Monochromatized Al-Kα ray Measurement region: 50 μmφ Measurement peak: C1s, O1s, N1s, P2p, Cu2p2/3, Zn2p2/3 Data treatment: Multipak Quantitation: quantitated from the obtained peak area by using relative sensibility coefficient method, * Cu/Zn is a ratio of quantitative values of Cu2p2/3 and Zn2p2/3. the belt layer has at least six belts laminated in a tire radial direction; a width of a third belt, which is arranged at a third position from an inner side in the tire radial direction among the belts, is set in range between 65% and 85% of a tire maximum width; a width of a fourth belt, which is arranged at a fourth position from the inner side in the tire radial direction among the belts, is set in range between 55% and 75% of the tire maximum width; each of the belts is formed of a metal cord-rubber composite formed by coating a plurality of metal cords with a rubber composition; characterized in that, the metal cord in each of the third belt and the fourth belt is formed such that N (nitrogen) atoms in a surface thereof is set in a range between 2 atom% and 60 atom% and a Cu/Zn ratio in the surface is set in a range between 1 and 4; and the rubber composition in each of the third belt and the fourth belt includes 1 part by mass to 15 parts by mass of silica and 0 parts by mass to 1 part by mass of cobalt-containing compound based on 100 parts by mass of a rubber component, wherein the N (nitrogen) atoms and the Cu/Zn ratio in a surface are measured using an X-ray photoelectron spectroscopy device under the measurement conditions set out below: X-ray source: Monochromatized Al-Kα ray Measurement region: 50 μmφ Measurement peak: C1s, O1s, N1s, P2p, Cu2p2/3, Zn2p2/3 Data treatment: Multipak Quantitation: quantitated from the obtained peak area by using relative sensibility coefficient method, * Cu/Zn is a ratio of quantitative values of Cu2p2/3 and Zn2p2/3. X-ray source: Monochromatized Al-Kα ray Measurement region: 50 μmφ Measurement peak: C1s, O1s, N1s, P2p, Cu2p2/3, Zn2p2/3 Data treatment: Multipak Quantitation: quantitated from the obtained peak area by using relative sensibility coefficient method, * Cu/Zn is a ratio of quantitative values of Cu2p2/3 and Zn2p2/3.