A weak light releasing layer includes a plurality of weak light releasing sections separated from each other by overlapping with corresponding one of the plurality of light releasing sections and a second inspection portion that is positioned relatively to the plurality of weak light releasing sections and overlaps with a first inspection portion. There are a first region and a second region that differ depending on whether or not there is an overlap with the second inspection portion inside an outer shape of the first inspection portion. The first region is sandwiched between any pair of portions of the second region in any of a plurality of directions orthogonal to each other.

A weak light releasing layer includes a plurality of weak light releasing sections separated from each other by overlapping with corresponding one of the plurality of light releasing sections and a second inspection portion that is positioned relatively to the plurality of weak light releasing sections and overlaps with a first inspection portion. There are a first region and a second region that differ depending on whether or not there is an overlap with the second inspection portion inside an outer shape of the first inspection portion. The first region is sandwiched between any pair of portions of the second region in any of a plurality of directions orthogonal to each other.

An exposure head includes a substrate assembly including a first light emitting chip, a second light emitting chip, and a substrate on which the first light emitting chip and the second light emitting chip are mounted, a lens array, a retaining member configured to retain the substrate assembly and the lens array, and a first adhesion portion. In a state where an area on the substrate where the end portion of the second light emitting chip in the main scanning direction and the end portion of the first light emitting chip in the main scanning direction overlap when viewed in the sub-scanning direction is referred to as a first area, the first adhesion portion is configured to adhere both end portions of the substrate assembly in the sub-scanning direction to the retaining member in the first area.