A frame structure includes three or more supporting members, a scanner support, a scanner cantilever support, and an adjuster. Three or more supporting members are provided vertically from a base portion. The scanner support is provided horizontally between upper portions of the supporting members. The scanner cantilever support extends horizontally from the upper portion of one of the supporting members. The adjuster is attached to a free end of the cantilever support, and includes an inclined slot. The cantilever support includes a protrusion provided in the free end of the scanner cantilever support. The protrusion is engageable with the slot of the adjuster to obliquely raise and lower the adjuster.