A charged particle spin polarimeter that is capable of resolving with high efficiency the magnetic moment of a charged particle. The charged particle spin polarimeter has a pair of convex and concave magnetic poles to apply a magnetic field with gradient to an incident charged particle and a pair of plain plate electrodes to apply, to a charged particle, an electric field for canceling a Lorentz force that the charged particle receives from the magnetic field. The magnetic moment in the magnetic field direction of a charged particle is resolved by the interaction between the gradient of the magnetic field and the magnetic moment of the charged particle.