A method for transmitting/receiving data with transfer obligation delegated in a Wireless Sensor Network (WSN) reduces the time and power spent by a transmitting apparatus to wait for acknowledgment that a data transfer was successful. The method for transmitting data from a transmitting end to a receiving end through a set transfer route by multiple data transmit/receive apparatuses provided in a Wireless Sensor Network (WSN), typically includes the steps of: performing temporary storage of data to be transmitted on receiving a request to transmit data; requesting a data transmit/receive apparatus, existing on a next route, to transmit data while transmitting data to a data transmit/receive apparatus which is set as a transfer route; and confirming the delivery of the data to the data transmit/receive apparatus set as the transfer route, and then deleting the temporarily stored data frame.