An image forming apparatus includes: an apparatus main body that is provided with an image forming section that forms image on a sheet; a first guide member that guides the sheet along a sheet conveying path and is configured to be displaceable relative to the apparatus main body; a second guide member that guides the sheet along the sheet conveying path and is configured to be displaceable relative to the apparatus main body; and a single detecting unit that detects that both of the first guide member and the second guide member are respectively disposed at normal guide positions for guiding the sheet.