An image forming apparatus having a first power state and a second power state in which power consumption is lower than in the first power state includes a detection unit configured to detect an object present in a vicinity of the image forming apparatus, an receiving unit configured to receive a user's operation, a control unit configured to, if the object is detected by the detection unit or if the receiving unit receives the user's operation, shift the image forming apparatus from the second power state to the first power state, and a display unit configured to, if the image forming apparatus is shifted from the second power state to the first power state in response to receipt of the user's operation by the receiving unit, display information indicating that there is dust adhering to the detection unit.