A robot cleaner, comprising: a traveling unit configured to move a main body; a cleaning unit configured to execute cleaning; a camera configured to capture an image; a communication unit configured to exchange data with a mobile terminal or a server; and a controller configured to: when a mode command is received from the mobile terminal or the server, transmit a response message in response to the mode command to the mobile terminal or the server, control the traveling unit for the robot cleaner to travel based on a mode set according to the mode command, control the camera to capture an image during traveling, characterized in that the controller is further configured to control the communication unit to transmit the captured image and a conversation-type message related to the captured image to the mobile terminal or the server, the captured image including foreign substances, wherein the mode command is set through a conversation window displayed on the mobile terminal or the server, wherein the controller is further configured to: receive cleaning execution information from the mobile terminal or the server, execute cleaning of an area around the foreign substances based on cleaning execution information regarding the foreign substances, and control transmission of cleaning completion information to the mobile terminal, after completion of cleaning of the area around the foreign substances according to the cleaning execution information. a traveling unit configured to move a main body; a cleaning unit configured to execute cleaning; a camera configured to capture an image; a communication unit configured to exchange data with a mobile terminal or a server; and a controller configured to: when a mode command is received from the mobile terminal or the server, transmit a response message in response to the mode command to the mobile terminal or the server, control the traveling unit for the robot cleaner to travel based on a mode set according to the mode command, control the camera to capture an image during traveling, characterized in that the controller is further configured to control the communication unit to transmit the captured image and a conversation-type message related to the captured image to the mobile terminal or the server, the captured image including foreign substances, when a mode command is received from the mobile terminal or the server, transmit a response message in response to the mode command to the mobile terminal or the server, control the traveling unit for the robot cleaner to travel based on a mode set according to the mode command, control the camera to capture an image during traveling, characterized in that the controller is further configured to control the communication unit to transmit the captured image and a conversation-type message related to the captured image to the mobile terminal or the server, the captured image including foreign substances, wherein the mode command is set through a conversation window displayed on the mobile terminal or the server, wherein the controller is further configured to: receive cleaning execution information from the mobile terminal or the server, execute cleaning of an area around the foreign substances based on cleaning execution information regarding the foreign substances, and control transmission of cleaning completion information to the mobile terminal, after completion of cleaning of the area around the foreign substances according to the cleaning execution information. receive cleaning execution information from the mobile terminal or the server, execute cleaning of an area around the foreign substances based on cleaning execution information regarding the foreign substances, and control transmission of cleaning completion information to the mobile terminal, after completion of cleaning of the area around the foreign substances according to the cleaning execution information.