An electronic apparatus and an operation method thereof for determining a session duration time according to a characteristic of a response message in a chatbot are provided. The electronic apparatus is configured to determine a default session time based on a difficulty level of the response message, determine an additional session time based on conversation history information through the chatbot prior to outputting of the response message, determine a session duration time, which is a sum of the default session time and the additional session time, and provide the session duration time.