Periphery monitoring apparatus for work machine

A periphery monitoring apparatus for a work machine, comprising:

• a first detection element configured to detect an operation state of an operating device for operating the work machine by an operator;
• a second detection element configured to detect a position of an object existing around the work machine;
• a plurality of output devices that are arranged in a plurality of azimuths with reference to a location of the operator in a driving space of the work machine so as to correspond to respective azimuths of a plurality of target spaces with reference to the work machine, and that output an alarm to the operator;
• a first control element configured to determine a first designated target space that is at least a part of the plurality of target spaces, according to an action mode of the work machine which is predicted from the operation state detected by the first detection element;
• and
• a second control element configured to cause a first designated output device among the plurality of output devices, which is arranged in the driving space of the work machine corresponding to an azimuth of the first designated target space with reference to the work machine, to output a different alarm according to a varying mode of a relative position of the object with respect to the work machine, which is determined by a time series of a position of the object detected by the second detection element, in a case where a position of the object detected by the second detection element is included in the first designated target space determined by the first control element.