A copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120), comprising: copper particles; a dimethylglutaric acid; and a dispersion medium, wherein a content of the dimethylglutaric acid is 0.05 to 1.5% by mass on the basis of the total amount of the copper particles, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) contains submicro copper particles having a volume average particle diameter of 0.12 to 0.8 μm and flake-shaped micro copper particles having a maximum diameter of 2 to 50 μm and an aspect ratio of 3.0 or more as the copper particles, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) contains dihydroterpineol as the dispersion medium, and wherein a content of the submicro copper particles is 30 to 90% by mass on the basis of the total mass of the copper particles, and a content of the micro copper particles is 10 to 70% by mass on the basis of the total mass of the copper particles, and wherein a content of the dispersion medium is 5 to 20% by mass on the basis of the total mass of the copper paste for joining, and wherein a content of the dihydroterpineol is 60% by mass or more on the basis of the total mass of the dispersion medium, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) is for non-pressurization joining; wherein the volume average particle diameter means a 50% volume average particle diameter and is measured by the following method: first, metal particles serving as a raw material or dried metal particles obtained by removing a volatile component from the metal paste are dispersed in a dispersion medium by using a dispersant; next, the volume average particle diameter of the obtained dispersion element is measured by a light scattering-method particle size distribution analyzer; and wherein the maximum diameter of the flake-shaped micro copper particles is obtained from SEM images of the particles; the maximum diameter of the flake-shaped micro copper particles being obtained as a major axis X of the major axis of the flake-shaped micro copper particles; the major axis X being a distance of two parallel planes that are selected so that the distance between two parallel planes is the largest among two parallel planes circumscribing the flake-shaped micro copper particles in the three-dimensional shape of the flake-shaped micro copper particles. wherein a content of the dimethylglutaric acid is 0.05 to 1.5% by mass on the basis of the total amount of the copper particles, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) contains submicro copper particles having a volume average particle diameter of 0.12 to 0.8 μm and flake-shaped micro copper particles having a maximum diameter of 2 to 50 μm and an aspect ratio of 3.0 or more as the copper particles, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) contains dihydroterpineol as the dispersion medium, and wherein a content of the submicro copper particles is 30 to 90% by mass on the basis of the total mass of the copper particles, and a content of the micro copper particles is 10 to 70% by mass on the basis of the total mass of the copper particles, and wherein a content of the dispersion medium is 5 to 20% by mass on the basis of the total mass of the copper paste for joining, and wherein a content of the dihydroterpineol is 60% by mass or more on the basis of the total mass of the dispersion medium, and wherein the copper paste for joining (30, 110, 110a, 110b, 110c, 110d, 110e, 120) is for non-pressurization joining; wherein the volume average particle diameter means a 50% volume average particle diameter and is measured by the following method: first, metal particles serving as a raw material or dried metal particles obtained by removing a volatile component from the metal paste are dispersed in a dispersion medium by using a dispersant; next, the volume average particle diameter of the obtained dispersion element is measured by a light scattering-method particle size distribution analyzer; and wherein the maximum diameter of the flake-shaped micro copper particles is obtained from SEM images of the particles; the maximum diameter of the flake-shaped micro copper particles being obtained as a major axis X of the major axis of the flake-shaped micro copper particles; the major axis X being a distance of two parallel planes that are selected so that the distance between two parallel planes is the largest among two parallel planes circumscribing the flake-shaped micro copper particles in the three-dimensional shape of the flake-shaped micro copper particles.