1. An image display device comprising a memory and a processing circuit to execute a program for performing a process, the process comprising: acquiring a plurality of picked-up images with which image pick-up dates and/or times and an age are associated from the memory; registering a face image which shows a picked-up face and with which an image pick-up date and/or time is associated; detecting a face of each of the plurality of picked-up images acquired by the acquiring; calculating the degree of similarity between the face detected by the detecting and the face in the face image registered by the registering; reducing the degree of similarity of the face calculated by the calculating according to a degree of reducing in which the larger a difference between the image pick-up date and/or time associated with the picked-up image and the image pick-up date and/or time associated with the face image is, the larger the degree of reducing is and which is also based on the age; and first displaying the plurality of picked-up images acquired by the acquiring in descending order of degree of similarity, wherein the first displaying includes displaying a three-dimensional space having an axis of the degree of similarity and disposes the picked-up image at the position of the degree of similarity of the picked-up image reduced by the reducing on the three-dimensional space.