Disclosed is a mobile terminal provided with a security function. The mobile terminal provided with the security function can include: a casing having a data input portion for inputting data, and an upper casing and a lower casing which can be assembled and disassembled; a circuit board for processing input data, which is electrically connected to the data input portion and is provided with a security unit that requires security; a tamper prevention conductive portion which is arranged between the casing and the circuit board and is electrically connected to the circuit board when the upper casing and the lower casing are assembled; and a control portion for denying access to data in the security unit based on a resistance value of the tamper prevention conductive portion. As a result, access to data in a secure region to which important data is saved is denied when the casing is forcibly opened, thereby effectively preventing important data from being leaked to the outside.