An image forming apparatus comprising: a plurality of scanning targets (77BK-77M); an optical scanning section configured to scan the scanning targets with light to form electrostatic latent images on the scanning targets; a cassette configured to store sheets therein to which an image based on the electrostatic latent images is to be transferred; a cassette insertion section in which the cassette is inserted; and a cassette guide disposed in the cassette insertion section and configured to guide the cassette, wherein the optical scanning section includes a plurality of reflecting members (69BK-69M) corresponding one-to-one with the scanning targets and each configured to direct the light to a corresponding one of the scanning targets, the cassette guide includes one or more adjustment mechanisms (33Y-33M) that are equal in number to a prescribed number of reflecting members (69Y-69M) out of the plurality of reflecting members, the prescribed number of adjustment mechanisms corresponding one-to-one with the prescribed number of reflecting members and each being configured to adjust a position of a corresponding one of the reflecting members, each of the prescribed number of adjustment mechanisms includes a shaft member (28Y-28M) that extends in a longitudinal direction of the cassette guide, and a rotation mechanism (32Y-32M) linked to a tip portion of the shaft member and configured to rotate according to rotation of the shaft member, the optical scanning section further includes one or more link mechanisms (70Y-70M) that are equal in number to the prescribed number, the prescribed number of link mechanisms corresponding one-to-one with the prescribed number of adjustment mechanisms, each of the prescribed number of link mechanisms links a corresponding one of the rotation mechanisms to a corresponding one of the reflecting members and changes the position of the reflecting member according to rotation of the rotation mechanism, the cassette insertion section has an insertion slot, a base end face (23Y-23M) of each of the shaft members is located closer to the insertion slot than the tip portion of the shaft member, and the base end face of at least one of the shaft members has a shape conforming to a shape of a tool, the plurality of scanning targets are configured such that developer images are formed thereon with developers of different colors based on the electrostatic latent images formed by the optical scanning section, and the base end face of at least one of the shaft members has a color indicating a color of the developer image to be formed on a corresponding one of the scanning targets. a plurality of scanning targets (77BK-77M); an optical scanning section configured to scan the scanning targets with light to form electrostatic latent images on the scanning targets; a cassette configured to store sheets therein to which an image based on the electrostatic latent images is to be transferred; a cassette insertion section in which the cassette is inserted; and a cassette guide disposed in the cassette insertion section and configured to guide the cassette, wherein the optical scanning section includes a plurality of reflecting members (69BK-69M) corresponding one-to-one with the scanning targets and each configured to direct the light to a corresponding one of the scanning targets, the cassette guide includes one or more adjustment mechanisms (33Y-33M) that are equal in number to a prescribed number of reflecting members (69Y-69M) out of the plurality of reflecting members, the prescribed number of adjustment mechanisms corresponding one-to-one with the prescribed number of reflecting members and each being configured to adjust a position of a corresponding one of the reflecting members, each of the prescribed number of adjustment mechanisms includes a shaft member (28Y-28M) that extends in a longitudinal direction of the cassette guide, and a rotation mechanism (32Y-32M) linked to a tip portion of the shaft member and configured to rotate according to rotation of the shaft member, a shaft member (28Y-28M) that extends in a longitudinal direction of the cassette guide, and a rotation mechanism (32Y-32M) linked to a tip portion of the shaft member and configured to rotate according to rotation of the shaft member, the optical scanning section further includes one or more link mechanisms (70Y-70M) that are equal in number to the prescribed number, the prescribed number of link mechanisms corresponding one-to-one with the prescribed number of adjustment mechanisms, each of the prescribed number of link mechanisms links a corresponding one of the rotation mechanisms to a corresponding one of the reflecting members and changes the position of the reflecting member according to rotation of the rotation mechanism, the cassette insertion section has an insertion slot, a base end face (23Y-23M) of each of the shaft members is located closer to the insertion slot than the tip portion of the shaft member, and the base end face of at least one of the shaft members has a shape conforming to a shape of a tool, the plurality of scanning targets are configured such that developer images are formed thereon with developers of different colors based on the electrostatic latent images formed by the optical scanning section, and the base end face of at least one of the shaft members has a color indicating a color of the developer image to be formed on a corresponding one of the scanning targets.