An analyzer comprising: a specimen container setting portion including a plurality of container holders for holding a plurality of specimen containers of different types; an aspiration section for aspirating the specimen from the specimen container set in the specimen container setting portion; a sensor for detecting the presence of the specimen container set in at least one of the plurality of container holders; and a controller for determining in which of the plurality of container holders the specimen container is set based on the detection result of the sensor, and controlling the operation of the aspiration section, is disclosed. A method for aspirating a specimen is also disclosed.