The present disclosure provides a protective case for a mobile terminal, the protective case including: a mobile terminal case which has a box shape, and surrounds and protects a mobile terminal; an auxiliary battery case which is positioned outside a rear surface of the mobile terminal case, and defines a space for accommodating an auxiliary battery; a mobile terminal side contact terminal which is disposed on an inner surface of the mobile terminal case, and is in electrical contact with an external terminal of the mobile terminal; and an auxiliary battery side contact terminal which is disposed on an inner surface of the auxiliary battery case, and is in electrical contact with an external terminal of the auxiliary battery, in which electric power of the auxiliary battery is provided to the mobile terminal through a connecting cable that electrically connects the mobile terminal side contact terminal and the auxiliary battery side contact terminal.