An RoF [Radio over Fiber] transceiver for relaying and transmitting a radio signal in radio communication between a base station and a terminal via a fiber optic transmission line, the RoF transceiver comprising: an antenna unit configured to transmit and/or receive the radio signal; first amplifier configured to amplify a reception signal and generate a first electrical signal; an electrical-optical converter configured to convert the first electrical signal amplified by the first amplifier into a transmission optical signal and transmit the transmission optical signal to the fiber optic transmission line; an optical-electrical converter configured to convert a reception optical signal received via the fiber optic transmission line into a second electrical signal; a second amplifier configured to amplify the second electrical signal and generate a transmission signal; and a signal processor configured to input the transmission signal amplified by the second amplifier, wherein the signal processor includes: a branch unit configured to branch the transmission signal and acquire a branch signal; a detection unit configured to detect the branch signal and acquire a voltage value of the branch signal; a determination unit configured to compare the voltage value of the branch signal with a threshold voltage previously stored in a storage unit and determine whether the voltage value of the branch signal is equal to or greater than the threshold voltage; and a power source controller configured to control turning on and off of a power source for the first amplifier according to a determination result determined by the determination unit, wherein the power source controller is configured to turn off the power source when the voltage value of the branch signal is equal to or greater than the threshold voltage, and to turn on the power source when the voltage value of the branch signal is smaller than the threshold value. an antenna unit configured to transmit and/or receive the radio signal; first amplifier configured to amplify a reception signal and generate a first electrical signal; an electrical-optical converter configured to convert the first electrical signal amplified by the first amplifier into a transmission optical signal and transmit the transmission optical signal to the fiber optic transmission line; an optical-electrical converter configured to convert a reception optical signal received via the fiber optic transmission line into a second electrical signal; a second amplifier configured to amplify the second electrical signal and generate a transmission signal; and a signal processor configured to input the transmission signal amplified by the second amplifier, wherein the signal processor includes: a branch unit configured to branch the transmission signal and acquire a branch signal; a detection unit configured to detect the branch signal and acquire a voltage value of the branch signal; a determination unit configured to compare the voltage value of the branch signal with a threshold voltage previously stored in a storage unit and determine whether the voltage value of the branch signal is equal to or greater than the threshold voltage; and a power source controller configured to control turning on and off of a power source for the first amplifier according to a determination result determined by the determination unit, wherein the power source controller is configured to turn off the power source when the voltage value of the branch signal is equal to or greater than the threshold voltage, and to turn on the power source when the voltage value of the branch signal is smaller than the threshold value. a branch unit configured to branch the transmission signal and acquire a branch signal; a detection unit configured to detect the branch signal and acquire a voltage value of the branch signal; a determination unit configured to compare the voltage value of the branch signal with a threshold voltage previously stored in a storage unit and determine whether the voltage value of the branch signal is equal to or greater than the threshold voltage; and a power source controller configured to control turning on and off of a power source for the first amplifier according to a determination result determined by the determination unit, wherein the power source controller is configured to turn off the power source when the voltage value of the branch signal is equal to or greater than the threshold voltage, and to turn on the power source when the voltage value of the branch signal is smaller than the threshold value.