Provided are a method and a device for transmitting a downlink control signal in a wireless communication system. A base station sets a transmission/reception (Tx/Rx) period (TSPS) on the basis of the type of a machine to machine (M2M) application, transmits said set Tx/Rx period to an M2M device, and performs a permanent scheduling for said M2M device on the basis of said set Tx/Rx period. Alternatively, the base station transmits a first downlink control signal that is allocated for an M2M group, which includes a plurality of M2M devices, to an M2M device that is included in said M2M group, and transmits, to said M2M device, a second downlink control signal that is specific to and allocated to said M2M device.