Provided are an excellent cold cathode ionization gauge and an excellent cold cathode ionization gauge cartridge. The cold cathode ionization gauge includes: an anode; a cathode, which has a tubular shape, and is arranged to surround the anode; a seal for sealing one opening of the cathode; a first member, which faces the seal inside the cathode, and has a through hole formed therein; a partition for partitioning a space surrounded by the cathode, the seal, and the first member into a first space that the first member faces and a second space that the seal faces; and a light source, which is arranged in the partition or the second space, and is configured to emit an electromagnetic wave, in which a gap is formed between at least part of an outer peripheral portion of the partition and the cathode.