A Wien filter and a charged particle beam imaging apparatus are provided. The Wien filter Wien filter, including a Wien filter body which includes: an electrostatic deflector, including at least one pair of electrodes, respective two electrodes in each pair of which are opposite to each other, each electrode including an electrode body constructed in an arc-shaped form, and respective electrode bodies of respective two electrodes in each pair of the at least one pair of electrodes being arranged concentrically with and opposite to each other in a diameter direction, and the at least one pair of electrodes being configured to generate respective electric fields by cooperation of the respective two electrodes in each pair of the at least one pair of electrodes, in the condition of respective bias voltages applied individually thereon; and a magnetic deflector, including at least one pair of magnetic poles, respective two magnetic poles in each pair of which are opposite to each other, each magnetic pole including a magnetic pole body constructed in an arc-shaped form, and respective magnetic pole bodies of respective two magnetic poles in each pair of the at least one pair of magnetic poles being arranged concentrically with and opposite to each other in the diameter direction, and the magnetic pole bodies of the at least one pair of magnetic poles in the magnetic deflector and the electrode bodies of the at least one pair of electrodes in the electrostatic deflector being arranged concentrically and spaced apart from each other in a circumferential direction, and the at least one pair of magnetic poles being configured to generate respective magnetic fields by cooperation of respective two magnetic poles in each pair of the at least one pair of magnetic poles; a resultant electric field formed collectively by all of the respective electric fields is perpendicular to a resultant magnetic field formed collectively by all of the respective magnetic fields; and each electrode is also provided with a respective first protrusion extending radially inwards from a radial inner side of the respective electrode body thereof, and each magnetic pole is also provided with a second protrusion extending radially inwards from a radial inner side of the respective magnetic pole body thereof.