An image analyzer for detecting a target object from image data, includes a reference detection unit, a primary detection unit, a secondary detection unit and an output unit. The reference detection unit detects a reference object included in the image data. The primary detection unit detects candidates for the target object from the image data. The secondary detection unit specifies a portion including the target object from among the candidates, by using a correlation between a feature of the detected reference object and a feature of the candidates. The output unit outputs information representing the portion including the target object specified by the secondary detection unit.