Provided is an apparatus for monitoring a communication satellite, including: a receiver to receive at least one satellite service signal from a satellite repeater; a measurement unit to measure a frequency, a bandwidth, and a magnitude of the at least one satellite service signal; a controller to determine whether a signal transmitting station malfunctions by comparing the at least one satellite service signal with a predetermined reference value based on the measurement result; and a communication unit to inform an operator terminal about a malfunction of the signal transmitting station when the signal transmitting station is determined to malfunction.