Work machine and periphery monitoring system

In a hydraulic excavator including a machine body and a front work device, when an object is detected by sensors for detecting an object around the machine body when operation limiting control for limiting the operation of at least one of the machine body and the front work device is enabled, or when an operation device is operated, the detection of the object is notified to an operator by a first state warning, and when the operation limiting control is enabled and when the operation device is not operated, the detection of the object is notified to the operator by a second state warning that is weaker in warning intensity than the first state warning. Accordingly, the botheration for the operator can be suppressed while securing the effectiveness of an alarm in periphery monitoring, and the safety performance can be enhanced.