One aspect of the present invention provides a technology of acquiring a good tomographic image equal to an X-ray image obtained by intraoral radiography. An X-ray photography apparatus (1) includes: a turning arm (30) that supports an X-ray generator (10a) and an X-ray detector (21) while the X-ray generator (10a) and the X-ray detector (21) are opposed to each other with a head (M10) interposed therebetween； and a moving mechanism (200) that includes a turning part (201) and a moving part (202). The turning part (201) is configured to turn the turning arm (30) about a turning axis (31) with respect to the head (M10). The moving part (202) is configured to move the turning arm (30) relative to the head (M10) in a direction perpendicular to the turning axis (31). The X-ray photography apparatus (1) also includes: an image processor (801b) that is configured to generate an X-ray image based on an electric signal output from the X-ray detector (21)； a photographic region designation part (610) that designates part of a row of teeth along a dental arch (90) as a pseudo intraoral radiography region； and an X-ray forming mechanism (13) that is configured to change an irradiation direction in which the head (M10) is irradiated with an X-ray relative to an axial direction of a body axis (MX1).
