An electronic apparatus and a secure firmware update method thereof are provided. The electronic apparatus includes a first integrated circuit chip, a first non-volatile memory chip, a second integrated circuit chip and a second non-volatile memory chip. The first integrated circuit chip includes a secure firmware update console, and the first non-volatile memory chip includes a spare data storage space. The first non-volatile memory chip and the second non-volatile memory chip store a first firmware code of the first integrated circuit chip and a second firmware code of the second integrated circuit chip, respectively. Firmware code update data are transferred to and stored in the spare data storage space. The secure firmware update console performs a firmware update procedure by writing the firmware code update data into the second non-volatile memory chip to overwrite the second firmware code after passing a verification procedure on the firmware code update data.