An image forming apparatus, including: a decision unit configured to decide a size of a recording material on a manual feed tray; a storage unit configured to store the size of the recording material decided by the decision unit when the image forming apparatus is shifted from a first mode in which power is supplied to the decision unit to a second mode in which the power is not supplied to the decision unit; a display unit configured to display information; and a control unit configured to cause the display unit to display a screen for confirming the size of the recording material on the manual feed tray in a case where the size of the recording material decided by the decision unit when the apparatus is shifted from the second mode to the first mode does not match the size of the recording material stored in the storage unit.