A resin frame includes frame members combined into a frame shape that includes a corner portion, and a joint portion joining a pair of the frame members which are adjacent to each other at the corner portion. The joint portion includes an entire-surface welded portion, in which end surfaces of the pair of the frame members are welded to each other over an entire surface in a thickness direction of a plate portion of the frame members, and a partial welded portion, in which the end surfaces of the pair of the frame members are welded to each other on one side of the entire surface in the thickness direction while another side of the entire surface in the thickness direction is not welded. The entire-surface welded portion and the partial welded portion are present at different portions on an outer periphery of the joint portion.