A centrifugal compressor comprising: a first diffuser wall; a second diffuser wall that faces the first diffuser wall and forms a diffuser flow path between the first diffuser wall and the second diffuser wall; guide blades capable of protruding from the first diffuser wall into the diffuser flow path; and change means capable of changing a distance between the guide blades and the second diffuser wall in accordance with an airflow rate of the diffuser flow path, wherein the centrifugal compressor is equipped with at least one of a structure in which adjacent ones of the guide blades do not overlap with each other, when viewed from a center axis of the centrifugal compressor and a structure in which a throat is not formed between adjacent ones of the guide blades; and a distance between the guide blades and the second diffuser wall is smaller than a distance between the first diffuser wall and areas of the second diffuser walls that face the guide blades when the change means maximizes the distance between the guide blades and the second diffuser wall, the change means is configured to set the distance between the guide blades and the second diffuser wall to a first distance if the airflow rate of the diffuser flow path is equal to or larger than a predetermined value; the change means is configured to set the distance between the guide blades and the second diffuser wall to a distance smaller than the first distance if the airflow rate of the diffuser flow path is smaller than the predetermined value; characterized in that the change means is configured to chance the distance between the guide blades and the second diffuser wall from the first distance, and then returns the distance to the first distance, if a state in which the airflow rate is equal to or larger than the predetermined value continues for a predetermined time. a first diffuser wall; a second diffuser wall that faces the first diffuser wall and forms a diffuser flow path between the first diffuser wall and the second diffuser wall; guide blades capable of protruding from the first diffuser wall into the diffuser flow path; and change means capable of changing a distance between the guide blades and the second diffuser wall in accordance with an airflow rate of the diffuser flow path, wherein the centrifugal compressor is equipped with at least one of a structure in which adjacent ones of the guide blades do not overlap with each other, when viewed from a center axis of the centrifugal compressor and a structure in which a throat is not formed between adjacent ones of the guide blades; and a distance between the guide blades and the second diffuser wall is smaller than a distance between the first diffuser wall and areas of the second diffuser walls that face the guide blades when the change means maximizes the distance between the guide blades and the second diffuser wall, the change means is configured to set the distance between the guide blades and the second diffuser wall to a first distance if the airflow rate of the diffuser flow path is equal to or larger than a predetermined value; the change means is configured to set the distance between the guide blades and the second diffuser wall to a distance smaller than the first distance if the airflow rate of the diffuser flow path is smaller than the predetermined value; characterized in that the change means is configured to chance the distance between the guide blades and the second diffuser wall from the first distance, and then returns the distance to the first distance, if a state in which the airflow rate is equal to or larger than the predetermined value continues for a predetermined time.