A mobile terminal comprising: a touchscreen; a wireless communication unit configured to perform a wireless communication with at least one or more external terminals (100-1, 100-3) including a 1 st external terminal; and a controller configured to: receive a 1 st image message including an image from the 1 st external terminal, characterised in that the controller is configured to display the received 1 st image message in a message list on the touchscreen such that the received 1 st image message is added to the message list listing at least one of a previously saved message transmitted to the 1 st external terminal and a previously saved message received from the 1 st external terminal, in response to a 1 st user command inputted in the course of displaying the 1 st image message, control a 1 st memo to be written on the image of the received 1 st image message, in response to a 2 nd user command, transmit a 2 nd image message including the image having the 1 st memo written thereon to the 1 st external terminal, and display the transmitted 2 nd image message in the message list such that the transmitted 2 nd image message is further added to the message list listing the received 1 st image message and at least one of the previously saved transmitted message and the previously saved received message. a touchscreen; a wireless communication unit configured to perform a wireless communication with at least one or more external terminals (100-1, 100-3) including a 1 st external terminal; and a controller configured to: receive a 1 st image message including an image from the 1 st external terminal, characterised in that the controller is configured to display the received 1 st image message in a message list on the touchscreen such that the received 1 st image message is added to the message list listing at least one of a previously saved message transmitted to the 1 st external terminal and a previously saved message received from the 1 st external terminal, in response to a 1 st user command inputted in the course of displaying the 1 st image message, control a 1 st memo to be written on the image of the received 1 st image message, in response to a 2 nd user command, transmit a 2 nd image message including the image having the 1 st memo written thereon to the 1 st external terminal, and display the transmitted 2 nd image message in the message list such that the transmitted 2 nd image message is further added to the message list listing the received 1 st image message and at least one of the previously saved transmitted message and the previously saved received message. receive a 1 st image message including an image from the 1 st external terminal, characterised in that the controller is configured to display the received 1 st image message in a message list on the touchscreen such that the received 1 st image message is added to the message list listing at least one of a previously saved message transmitted to the 1 st external terminal and a previously saved message received from the 1 st external terminal, in response to a 1 st user command inputted in the course of displaying the 1 st image message, control a 1 st memo to be written on the image of the received 1 st image message, in response to a 2 nd user command, transmit a 2 nd image message including the image having the 1 st memo written thereon to the 1 st external terminal, and display the transmitted 2 nd image message in the message list such that the transmitted 2 nd image message is further added to the message list listing the received 1 st image message and at least one of the previously saved transmitted message and the previously saved received message.