PROBLEM TO BE SOLVED: To make a user properly notified of the timing of an exposure instruction according to a photographing mode.SOLUTION: An X-ray photographing apparatus includes an X-ray detector for detecting X rays emitted from an X-ray source. The X-ray detector has a plurality of driving states including a photographing preparation state for initializing a photoelectric conversion element, a photography permission state for inhibiting the initialization and waiting for an instruction to start photographing, and a photographing state. A drive control unit causes the driving state of the X-ray detector to transition according to the photographing mode selected from among a plurality of photographing modes each having a different combination of the driving state of the X-ray detector and a period in which exposure operation of the user is permitted. A notification unit notifies whether or not the driving state of the X-ray detector is in an exposure-permitted period in the driving state transition according to the selected photographing mode.
