The present invention relates to a method for handling the PIN code of the SIM card of a GSM terminal of a remote monitoring device used for remote monitoring of elevators and/or escalators and/or moving walkways. According to the present invention, when the aforesaid remote monitoring device and GSM terminal are to be taken in use, the aforesaid SIM card is assigned a public default PIN code and a randomly generated PIN code. By applying the present invention, the data security of the handling of the PIN code of the SIM card of the GSM terminal of the remote monitoring device is substantially improved.