An imaging apparatus includes an image creating section for imaging a predetermined surveillance range and creating image data, and a storage processing section converting the image data to a predetermined storage format and creating storage data. A data storage section having a storage medium with a predetermined storage space stores the storage data created by the storage processing section. The apparatus includes a compression processing section for reading storage data stored in the data storage section, and compressing the storage data and creating compressed data. A determination processing section detects the data storage amount of the storage data stored in the data storage section, supplies a compression control signal to the compression processing section in accordance with the detection result and supplies the storage control signal to the data storage section.