The inventive concept provides an apparatus for processing a substrate. The substrate processing apparatus may include a treatment chamber having a treatment space for processing a substrate therein; a support unit for supporting a substrate in the treatment space; a plasma generation chamber provided outside the treatment chamber and having a plasma generation space for generating plasma from treatment gas; a baffle disposed between the treatment space and the plasma generation space; and an ionization device for discharging a charge on a substrate supported on the support unit to remove a residual charge on the substrate.

Provided is a technique and the like capable of specifying irradiation areas or irradiation positions of a beam and a light as clearly as possible. A charged particle beam apparatus 1 includes: a position adjustment mark 10 provided on a stage 6 and irradiated with a beam bl and a light a1; and a mechanism setting an irradiation position of the beam bl and an irradiation position of the light a1 with respect to the stage 6 and changing a relative positional relationship including a distance between the irradiation position of the light a1 and the stage 6. A computer system 2 generates a first image in which the position adjustment mark 10 is reflected based on a first detection signal obtained by irradiating the position adjustment mark 10 with the beam b1, generates a second image in which an irradiation area of the light a1 is reflected in the vicinity of the position adjustment mark 10 based on a second detection signal obtained by irradiating the position adjustment mark 10 with the light a1, and adjusts an irradiation position of the beam b1 and an irradiation position of the light a1 based on the first image and the second image obtained when a positional relationship is changed by the mechanism.