To provide a portable ion generator which can raise generation efficiency of a negative ion while keeping a simple construction, which includes electrical discharge means 12 in a predetermined case body 10, and which blows out the negative ion generated by the discharging means 12 through an ion discharging port 24 to the outside of the case body 10.

A discharge electrode 16 capable of generating the negative ion by applying a high voltage with minus polarity and a counter electrode 20 placed near the discharge electrode 16 are equipped inside the case body 10. An auxiliary electrode 22 is arranged in the negative ion generator while being exposed to the outer periphery face of the case body 10 and in the negative ion generator, the counter electrode 16 and the auxiliary electrode 22 are connected to an earth line 18 inside the case body.