To realize an imaging apparatus and its program which can reduce the blur of an image and the degradation of image quality.

In the imaging apparatus, based on brightness of a subject obtained by photometric processing performed when a capture frame period arrives, and an ordinary gain value, an exposure time TL and a diaphragm value are calculated and photographing is carried out by use of the calculated exposure time TL, diaphragm value, and ordinary gain value (S32 to S33). Then, a gain value corresponding to a difference between a predetermined, relatively short exposure time TS and the exposure time TL is calculated, and photographing is carried out at the calculated gain value, for the predetermined exposure times TS, and at the diaphragm value calculated in S33 (S36, 37). Then, by comparing images picked up before and after an image Ln picked up for the exposure time TL, and thereby an amount of blur of the image Ln is detected (S38). If the amount of blur of the image Ln is a predetermined value or larger, an image Sn picked up for the exposure time TS is recorded (S40, 42). If the amount of blur is not the predetermined value or larger, the image Sn is recorded (S41, 42).