A work machine having a machine body with a propulsive device, a multi-joint work implement mounted on the machine body and including a plurality of front members that are angularly movably interconnected, and an operating device configured for outputting operating signals configured for operating the work implement, the work machine comprising: a GNSS receiving device mounted on the machine body configured for acquiring positional information of the work machine; at least one magnetic field generating device fixed to the machine body at a predetermined position, configured for generating a magnetic field signal including a magnetic field ID configured for identifying a source configured for generating the magnetic field signal; a tag information receiving device configured for receiving a radio-wave signal sent from at least one worker tag carried by the operator of the work machine and a worker working outside of the work machine and having a GNSS receiving section configured for acquiring positional information of the worker tag, the worker tag being responsive to the magnetic field signal generated by the magnetic field generating device configured for sending the radio-wave signal that includes at least the magnetic field ID included in the received magnetic field signal, a tag ID configured for allowing the worker tag that has received the magnetic field signal to identify itself, and positional information of the worker tag; a tag detecting device controller configured for controlling the magnetic field generating device with a detection command, acquiring information included in the radio-wave signal received by the tag information receiving device, and outputting the acquired information as detected tag information; and a controller configured for determining a detection target area where a position of a worker tag with respect to the work machine is a detection target, and a proximity notification target area where proximity of a worker tag is a proximity notification target in the detection target area, calculating the position of a worker tag with respect to the work machine based on the positional information of the work machine, the positional information of the worker tag, the detected tag information acquired by the tag detecting device control section, and the detection target area, and generating a notification command and outputting the generated notification command to a notification device to notify the operator of the work machine of the detection of the worker tag in case the worker tag is detected in the proximity notification target area. a GNSS receiving device mounted on the machine body configured for acquiring positional information of the work machine; at least one magnetic field generating device fixed to the machine body at a predetermined position, configured for generating a magnetic field signal including a magnetic field ID configured for identifying a source configured for generating the magnetic field signal; a tag information receiving device configured for receiving a radio-wave signal sent from at least one worker tag carried by the operator of the work machine and a worker working outside of the work machine and having a GNSS receiving section configured for acquiring positional information of the worker tag, the worker tag being responsive to the magnetic field signal generated by the magnetic field generating device configured for sending the radio-wave signal that includes at least the magnetic field ID included in the received magnetic field signal, a tag ID configured for allowing the worker tag that has received the magnetic field signal to identify itself, and positional information of the worker tag; a tag detecting device controller configured for controlling the magnetic field generating device with a detection command, acquiring information included in the radio-wave signal received by the tag information receiving device, and outputting the acquired information as detected tag information; and a controller configured for determining a detection target area where a position of a worker tag with respect to the work machine is a detection target, and a proximity notification target area where proximity of a worker tag is a proximity notification target in the detection target area, calculating the position of a worker tag with respect to the work machine based on the positional information of the work machine, the positional information of the worker tag, the detected tag information acquired by the tag detecting device control section, and the detection target area, and generating a notification command and outputting the generated notification command to a notification device to notify the operator of the work machine of the detection of the worker tag in case the worker tag is detected in the proximity notification target area.