A charged particle beam apparatus includes a tilt mechanism that tilts a specimen, a detector that detects an electromagnetic wave emitted from the specimen, a table storage unit that stores a table in which tilt angle information on a tilt angle of the specimen and detection solid-angle information on the detection solid angle of the detector are associated with each other, a tilt control unit that controls the tilt mechanism, and a detection-solid-angle information acquisition unit that acquires the tilt angle information from the tilt control unit and acquires the detection solid-angle information with reference to the table.