A mobile terminal includes a casing having an upper casing and a lower casing which are disassembled from and assembled to each other with respect to a main board, a connection terminal portion sealed with the casing to prevent intrusion of water through a gap between the connection terminal portion and the casing and having a plurality of connection terminals having one side exposed to the outside of the casing, and a joint terminal portion electrically connected to the main board and having a plurality of joint terminals respectively and electrically connected to the connection terminals in an elastically pressed state when the upper casing and the lower casing are assembled to each other.