This compact binding device is such that binding operations can be carried out when the main body of the device is held. The binding device (1A) is provided with a cassette storage unit (60A) in which a cassette (8) can be detachably attached, said cassette housing an elongate tape (5) which has a piece (2) adhered thereto and is wound into a roll. The cassette housing unit (60A) is provided at the bottom of the device main body (110A), which comprises a base unit (11A) and a handle unit (12), and the cassette (8) does not protrude rearwards from the handle unit (12) and the base unit (11A).