An account book service providing apparatus using a messaging service includes a first data receiver configured to receive first data input into a messenger chat window displayed on a terminal of a user, the first data including an income or expenditure detail; a second data processor configured to extract second data having a preset format from the first data and store the second data; an account book data storage unit configured to store the second data to be mapped to the user; a third data extractor configured to extract third data to reflect the second data, the third data including the sum of a total or some of the second data; and a data transmitter configured to transmit the second data or the third data to the terminal of the user so as to display the second data or the third data on the terminal of the user.