Provided is a method and system for providing an answer message to a query message. An answer message providing method may include managing a plurality of chatrooms of an instant messaging service; receiving a query message in a preset form from a first user of a first chatroom among the plurality of chatrooms; forwarding the query message to second users through the instant messaging service; receiving an answer message to the query message from at least one of the second users; and providing the received answer message to be displayed through the first chatroom.