A portable information terminal and an image management program are provided. A portable information terminal includes: a display part which has a screen capable of displaying at least an image; an in-focus value computing part which computes an in-focus value from an original image; an image cutting part which cuts a thumbnail image from the original image based on the in-focus value computed at the in-focus value computing part; a data storage part which stores data of the thumbnail image cut at the image cutting part; and a control part which reads the data of the thumbnail image stored in the data storage part as necessary and displays it on a screen of the display part.