An image forming apparatus includes an apparatus body, a sheet supporting portion, a sheet feeding portion configured to feed a sheet supported on the sheet supporting portion, a sheet regulation portion configured to regulate a position of the sheet in a width direction, an image forming portion including an exposing portion configured to expose a charged surface of an image bearing member, the image forming portion being configured to form an image on the sheet fed by the sheet feeding portion, and a frame member provided inside the apparatus body. A position of the exposing portion is determined with respect to the frame member. A position of the sheet regulation portion is determined with respect to the frame member.

An image forming apparatus includes an apparatus body, a sheet supporting portion, a sheet feeding portion configured to feed a sheet supported on the sheet supporting portion, a sheet regulation portion configured to regulate a position of the sheet in a width direction, an image forming portion including an exposing portion configured to expose a charged surface of an image bearing member, the image forming portion being configured to form an image on the sheet fed by the sheet feeding portion, and a frame member provided inside the apparatus body. A position of the exposing portion is determined with respect to the frame member. A position of the sheet regulation portion is determined with respect to the frame member.