Patent ID: 8785890

Claim:
A charged particle beam apparatus, comprising: a stage for placing a sample thereon; a detector detecting secondary charged particles generated due to irradiate a primary charged particle beam to the sample; an objective lens that focuses the primary charged particle beam on the sample and having an opening through which the primary charged particle beam passes; and a power supply unit applying a negative voltage to the sample, wherein the objective lens includes: a first magnetic pole member that is disposed around the opening and has a terminal portion at a sample side thereof that functions as an upper magnetic pole member of the objective lens; a second magnetic pole member that supplies a magnetic flux to the first magnetic pole member and is formed with a hollow interior; a coil that is disposed within the second magnetic pole member and supplies a magnetic flux to the second magnetic pole member; and a third magnetic pole member that is disposed between the stage and the second magnetic pole member, has the opening and functions as lower magnetic pole member of the objective lens, and wherein a potential lower than that of the second magnetic pole member is supplied to the third magnetic pole member.