An X-ray imaging apparatus comprising: an X-ray generator; an X-ray detector; a support that supports said X-ray generator and said X-ray detector while opposing said X-ray generator and said X-ray detector to each other; a turning driving unit that turns said X-ray generator and said X-ray detector supported by said support; a head holder that holds a head of a subject; a mode setting receiving unit (800, 82) that receives selection of a mode among a plurality of modes including a panoramic mode in which a curved section corresponding to a dental arch is imaged and a CT mode in which a predetermined imaging region is imaged; and an X-ray beam shape adjuster that adjusts a shape of an X-ray beam emitted from said X-ray generator according to the mode of which the selection is received by said mode setting receiving unit (800, 82), wherein said X-ray beam shape adjuster shapes the X-ray beam into an X-ray cone beam in which a center beam that is a center of the X-ray beam is incident orthogonally to a body axis of said head in said CT mode, characterized in that said X-ray beam shape adjuster shapes the X-ray beam into an X-ray narrow beam in which a center beam that is a center of the X-ray beam is incident upward from below with respect to said body axis, said X-ray narrow beam having a length in a direction of said body axis, in said panoramic mode, and in that the X-ray imaging apparatus further comprises a magnification ratio changing mechanism that changes a magnification ratio by relatively moving said X-ray detector with respect to said head held by said head holder, wherein said magnification ratio changing mechanism decreases the magnification ratio in said panoramic mode as compared with the magnification ratio in said CT mode. an X-ray generator; an X-ray detector; a support that supports said X-ray generator and said X-ray detector while opposing said X-ray generator and said X-ray detector to each other; a turning driving unit that turns said X-ray generator and said X-ray detector supported by said support; a head holder that holds a head of a subject; a mode setting receiving unit (800, 82) that receives selection of a mode among a plurality of modes including a panoramic mode in which a curved section corresponding to a dental arch is imaged and a CT mode in which a predetermined imaging region is imaged; and an X-ray beam shape adjuster that adjusts a shape of an X-ray beam emitted from said X-ray generator according to the mode of which the selection is received by said mode setting receiving unit (800, 82), wherein said X-ray beam shape adjuster shapes the X-ray beam into an X-ray cone beam in which a center beam that is a center of the X-ray beam is incident orthogonally to a body axis of said head in said CT mode, characterized in that said X-ray beam shape adjuster shapes the X-ray beam into an X-ray narrow beam in which a center beam that is a center of the X-ray beam is incident upward from below with respect to said body axis, said X-ray narrow beam having a length in a direction of said body axis, in said panoramic mode, and in that the X-ray imaging apparatus further comprises a magnification ratio changing mechanism that changes a magnification ratio by relatively moving said X-ray detector with respect to said head held by said head holder, wherein said magnification ratio changing mechanism decreases the magnification ratio in said panoramic mode as compared with the magnification ratio in said CT mode.