A sheet feeding device includes a cassette and a first sensor unit. The first sensor unit includes a first conductive plate and a first coil circuit board, so as to output a first output value corresponding to a position of the first conductive plate. A first moving mechanism moves the first conductive plate according to remaining quantity of paper sheets. The first conductive plate is attached to the cassette. The first coil circuit board is not attached to the cassette. A control unit determines current remaining quantity of paper sheets based on a magnitude of the first output value. The control unit determines whether or not the cassette is attached based on the magnitude of the first output value and a reference value.