Abstract: A phase shifting device, an antenna unit and abase station are disclosed. According to an embodiment, the phase shifting device comprises a power divider and a phase shifter. The power divider comprises an input inlet for an input signal, a first output outlet connected with an impedance member having a system impedance, and a second output outlet connected with the phase shifter. The phase shifter comprises a first plate and a second plate slidable relative to the first plate. Two parallel microstrip lines are provided on a first surface of the first plate. An adjusting member is provided on a second surface of the second plate that faces to the first surface of the first plate.