Near-infrared absorbing glass and near-infrared cutoff filter

Near-infrared absorbing glass, comprising at least, as constituent ions,

• P ions;
• Cu ions;
• O ions;
• optionally, Al ions;
• one or more ions selected from the group consisting of Li ions, Na ions and K ions;
• and
• one or more ions selected from the group consisting of Mg ions, Ca ions, Sr ions and Ba ions,
• wherein, in a glass composition expressed in cation %,
• a content of Na ions is 0 cation % or higher and 1.0 cation % or lower;
• a content of Cu ions is 5.1 cation % or higher and 15.0 cation % or lower;
• a content of P ions is 55.0 cation % or lower;
• a cation ratio of a total content of Al ions and P ions relative to a total content of Mg ions, Ca ions, Sr ions, Ba ions, Zn ions and Cu ions ((Al ions+P ions)/(Mg ions+Ca ions+Sr ions+Ba ions+Zn ions+Cu ions)) is 5.300 or lower;
• a cation ratio of a total content of Mg ions, Ca ions, Sr ions and Ba ions relative to a total content of Li ions, Na ions and K ions ((Mg ions+Ca ions+Sr ions+Ba ions)/(Li ions+Na ions+K ions)) is 0.100 or higher;
• an average valence of cations excluding Cu ions and P ions is lower than 1.500;
• and
• in a glass composition expressed in anion %,
• a content of O ions is 85.0 anion % or higher, and
• a ratio of the content of O ions relative to a content of P ions (O ions/P ions) is 3.300 or higher.