The present disclosure relates to a method for M2M devices in an idle mode to perform a network reentry procedure in a wireless access network supporting machine-to-machine communication (M2M), and the method may include receiving information related to selection of a group delegate (GD) from a base station; receiving a response to a ranging request from the base station, wherein the ranging request is transmitted by an M2M device which is selected as the GD among a plurality of M2M devices in an M2M device group based on the information related to selection of the GD; and performing a network reentry procedure on the basis of the received response.