A biopsy device includes a support base for supporting a mass to be examined, a compression plate for compressing and holding the mass to be examined against the support base, and a biopsy needle moving mechanism for moving a biopsy needle in a plane along the compression plate as well as in directions perpendicular to the compression plate. The biopsy needle is movable through an opening defined in the compression plate for insertion into the mass to be examined. The biopsy device also includes a determining section for determining whether or not the biopsy needle has pierced the mass to be examined, and a movement limiter for limiting movement of the biopsy needle within a plane perpendicular to a piercing direction along which the biopsy needle pierces the mass to be examined, if the determining section judges that the biopsy needle has pierced the mass to be examined.
