A fitting structure for fitting a plate-form member to a fitting destination member such that a position of the plate-form member relative to a target member is adjustable, the fitting structure has an adjustment pin inserted, in a fashion movable in a position adjustment direction, in an adjustment hole formed in the plate-form member; and a screw member for fastening the plate-form member to the fitting destination member, wherein a direction of a force of the screw member that acts upon the plate-form member when the screw member is in a position where the screw member fastens the plate-form member points from a side where a gap formed between the adjustment pin and the adjustment hole is smaller to a side where the gap is larger.