Testing apparatus for an early streamer emission device of a lightning arrester, the testing apparatus comprising: - an emitting unit configured to be installed in a lightning arrester, incorporating power supply means and energy storage means, and - a wireless receiving unit comprising a receiving antenna, and a signal demodulator to demodulate the signal obtained by the same, characterized in that the emitting unit further comprises a control and processing element (10.1) configured to generate a set of pulses with a time having a configurable value that attacks the early streamer emission device of the lightning arrester and also configured to activate said early streamer emission device and process the resulting frequency response, a measurement circuit configured to measure the frequency response of the early streamer emission device of the lightning arrester, a testing module configured to be activated by the control and processing element (10.1), an analog-to-digital converter configured to convert the analog signal obtained from the test performed on the early streamer emission device before processing, a modulator circuit configured to modulate the signal and a transmitting antenna configured to transmit the previously modulated processed data; - wherein the control and processing element (10.1) is programmed to activate the early streamer emission device test, performed by the testing module, every configurable time interval t1, keeping the emitting unit in a standby state during a configurable time interval t2, wherein t2 being less than t1, and to activate the sending of a result of a new test every time t1 and the sending of the repeated result of the last test performed every time t2; - and wherein the receiving unit further comprises identification means configured to identify the different states of the lightning arrester, an internal memory adapted to allow storing the data of successive tests performed, and an external connector adapted to extract said data into a data processing device. - an emitting unit configured to be installed in a lightning arrester, incorporating power supply means and energy storage means, and - a wireless receiving unit comprising a receiving antenna, and a signal demodulator to demodulate the signal obtained by the same, characterized in that the emitting unit further comprises a control and processing element (10.1) configured to generate a set of pulses with a time having a configurable value that attacks the early streamer emission device of the lightning arrester and also configured to activate said early streamer emission device and process the resulting frequency response, a measurement circuit configured to measure the frequency response of the early streamer emission device of the lightning arrester, a testing module configured to be activated by the control and processing element (10.1), an analog-to-digital converter configured to convert the analog signal obtained from the test performed on the early streamer emission device before processing, a modulator circuit configured to modulate the signal and a transmitting antenna configured to transmit the previously modulated processed data; - wherein the control and processing element (10.1) is programmed to activate the early streamer emission device test, performed by the testing module, every configurable time interval t1, keeping the emitting unit in a standby state during a configurable time interval t2, wherein t2 being less than t1, and to activate the sending of a result of a new test every time t1 and the sending of the repeated result of the last test performed every time t2; - and wherein the receiving unit further comprises identification means configured to identify the different states of the lightning arrester, an internal memory adapted to allow storing the data of successive tests performed, and an external connector adapted to extract said data into a data processing device.