Provided is a universal joint capable of freely regulating a mounting angle of one member with respect to the other member, and an image display unit using the same. The image display unit (1) includes an image display unit main body (100) having a convex surface (101) forming a part of a specific spherical surface, and an intermediate member (200). The intermediate member (200) includes a guide member (220) having a concave surface (221) that is a curved surface corresponding to the convex surface (101) and is supposed to come into contact with the convex surface (101) when the image display unit main body (100) and the intermediate member (200) are fixed to each other, and a magnet (230) provided at a position substantially the center of the guide member (220) and capable of being fixed to the convex surface (101) by attraction. When this convex surface (101) is allowed to slide on the concave surface (221), a mounting angle of the image display unit main body (100) with respect to the intermediate member (200) can be regulated.