PURPOSE: To grasp the advance state of photographing even at the time of photographing the heart rate synchronization by providing a measuring part for a repeat time of a trigger signal synchronized with an R wave, and an arithmetic display part for calculating and displaying the time required for photographing of one screen, based on an output repeat time or a set time of a prescribed period of this measuring part, and the photographing remaining time based on the calculated value of the trigger signal.

CONSTITUTION: A photographing time counter 41 reads out time from a counter 22 of a prescribed period control part 20 side and integrates it, whenever a trigger signal 11S is inputted, and counts a photographing time (Tn). The obtained photographing time Tn is divided by the count number N of the trigger signal from a view counter 32 by a dividing circuit 42 and an average value T=Tn/N of a repeat time is derived, and a result of operation is read by a detecting part 43 of an R wave period. Accordingly, the repeat time obtained by a measuring part 40 of an R wave period shows its average value, when the hear rate cycle is fluctuated.