A laser apparatus includes an optical element disposed on a laser beam axis, an actuator configured to displace the optical element to displace the laser beam axis, a driving amount monitor configured to monitor a driving amount of the actuator, an optical axis monitor disposed along the laser beam axis and configured to monitor the laser beam axis, and a control unit configured to control the actuator based on a monitoring result of the optical axis monitor and determine abnormality of the optical element based on a monitoring result of the driving amount monitor.