A charged particle beam apparatus automatically prepares a sample piece from a sample and includes a charged particle beam irradiation optical system that irradiates a charged particle beam to a sample placed on a movable sample stage. A sample piece transferring unit holds and transfers a sample piece separated and extracted from the sample, and a holder support holds a sample piece holder to which the sample piece is transferred. A computer controls a position of an object based on a template prepared from an image of the object acquired by irradition with the charged particle beam and position information acquired from the image of the object. The sample piece transferring unit includes a needle that transfers the sample piece separated and extrated from the sample, and a needle actuting mechanism that actuates the needle. The computer controls the needle actuating mechanism so as to approach the needle to the sample piece using the template formed from an absorbed current image acquired by irradiating the needle with the charged particle beam.