An analyzer capable of preventing unintended removal of a separation column is provided. A liquid chromatograph includes: a plurality of separation columns, and that are connected in parallel and removable; a plurality of analysis flow passages that are respectively connected to the plurality of separation columns and configured to allow a sample to flow through each of the plurality of separation columns; a lock mechanism that is configured to restrict removal of the separation columns and other than the separation column to be removed; and a control device that is configured to control the lock mechanism.