Copper electrode material

1. A copper electrode material, the copper electrode material comprising Cu which has a purity of 99.9999% by mass or more, excluding gas components, wherein an average crystal grain diameter of Cu is 20 μm or less,

wherein the copper electrode has a S content of 0.1 parts per million (ppm) by mass or less,

wherein the copper electrode material has a number of pores having a pore diameter of 10 μm or more of less than 1 pore/cm 2 as observed by an optical microscope.

2. The copper electrode material according to claim 1 , wherein the copper electrode has a P content of 0.1 ppm by mass or less, a Fe content of 0.1 ppm by mass or less, and an Al content of 0.1 ppm by mass or less.

3. The copper electrode material according to claim 1 , wherein the copper electrode material contains as gas components a C content of less than 1 ppm by mass and a O content of less than 1 ppm by mass.

4. The copper electrode material according to claim 1 , wherein the copper electrode material has a number of particles (LPC) of 1000 [pieces/g] or less.

5. The copper electrode material according to claim 1 , wherein the copper electrode material has a S content of less than 0.05 ppm by mass, a Fe content of less than 0.1 ppm by mass, a Co content of less than 0.05 ppm by mass, a Ni content of less than 0.1 ppm by mass, an As content of less than 0.005 ppm by mass, a Rh content of less than 1 ppm by mass, a Ag content of less than 1 ppm by mass, a Sn content of less than 0.5 ppm by mass, an Sb content of less than 0.005 ppm by mass, a Te content of less than 0.05 ppm by mass, a TI content of less than 0.5 ppm by mass, a Pb content of less than 0.05 ppm by mass, and a P content of less than 0.05 ppm by mass.