An image processing device 20 acquires captured images obtained by imaging a sample including a target cell, performs machine learning based on a first image feature quantity, sets a plurality of object regions for detecting the target cell in the captured images, and displays the plurality of object regions in an order determined based on the first image feature quantity of each of the plurality of object regions. The image processing device 20 calculates a second image feature quantity in each of the plurality of object regions, sorts the plurality of displayed object regions in an order of the second image feature quantity similar to the second image feature quantity of a reference object region selected from among the plurality of object regions, and displays the plurality of object regions.