The purpose of the present invention is to provide a charged particle beam irradiation apparatus of a relatively simple structure which performs cooling on a sample or a sample stage. An aspect of the present invention comprises: a charged particle source; a sample stage; and a driving mechanism that comprises a transmission mechanism which transmits a driving force to move the sample stage. The charged particle beam irradiation apparatus comprises a container capable of accommodating an ionic liquid (12), wherein the container is disposed in a vacuum chamber. When the ionic liquid (12) is accommodated in the container, at least a portion of the transmission mechanism is provided at a position submerged in the ionic liquid (12).