An image compression circuit provided in an image pickup apparatus for generation of compressed image data for record can also serve as an evaluation value calculation circuit that generates a contrast evaluation value to be used as an index for finding an in-focus location for an autofocus process. The image pickup apparatus includes a shooting optical system, an image pickup unit, an image compression unit, and a focusing unit. The image pickup unit has an image pickup device that performs photoelectric conversion of a subject image formed by the shooting optical system, and performs A/D conversion of a captured image obtained by the image pickup device to generate digital captured image data. The image compression unit performs an image compression process on the digital captured image data to generate compressed image data for focusing. The focusing unit adjusts the imaging location of the subject image formed by the shooting optical system on the basis of the data size of the compressed image data for focusing generated by the image compression unit.