A monitoring device 100 comprises a control unit 101 including a positional information acquisition section 101A that tracks an existing position of the communication terminal 120 and acquires positional information of the communication terminal 120 and a jurisdiction retaining section 101B that retains a jurisdictional district to receive an emergency telephone call where a building under security exists, an input/output unit 102 that detects an emergency situation based on a sensor output from the input/output device 110, and an alarm sending unit 103 that reports an e-mail transmission or an image via the telephone line 130. The control unit 101, when having detected an emergency situation, performs control to specify a communication terminal 120 that exists in the police jurisdictional district or fire jurisdictional district with reference to the jurisdiction retaining section 101B, and to report preferentially to the specified communication terminal 120. Accordingly, reporting preferentially to a mobile phone within a jurisdictional district where a building under security exists allows promptly reporting when an emergency call is made from the mobile phone.